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Electro-Plating and 
Analysis of Solutions 



A manual of information and 
instruction written for the 
benefit of the electro-plater and 
those interested in the art of 
electro-plating who wish to know 
something of the chemistry 
of electrolytic processes 

By Herman H. Reama 

Brooklyn, N. Y. 



The Metal Industry Print 
99 John Street, New York 






Copyrighted 1913 

Herman H. Reama 

Brooklyn, N. Y. 



©CI.A35 5 21 



PREFACE. 

In compiling this book I have endeavored 
to make it practical in every detail, wording it 
in concise and simple language, and avoiding 
technical terms as much as possible. 

I trust it will prove of benefit to my patrons, 
and in fact platers in general. 

Herman H. Reama. 
Brooklvn, N. Y. 1913. 



INTRODUCTION 

I now wish to introduce a few of my ideas 
in regard to electro-plating, and incidentally 
a few ideas dealing with those points in chem- 
istry which are of most benefit in the plating 
room. 

My idea is to write a book entirely on plat- 
ing and the analysis of plating solutions in 
general, which I know will be of great benefit 
to a plater. 

I shall be as brief as possible in all my work, 
as simple methods are more easily grasped by 
the ordinary plater than difficult formulas 
that can only be understood by a graduate 
chemist. 

I trust the readers will appreciate that the 
information contained in this book is only in- 
troduced with the idea of helping those who 
follow this line of business to acquire more 
skill in the plating line. 

The sources of current used for electroplat- 
ing are the dynamo and the battery. Until the 
introduction of plating dynamos about sixty 
years ago, electro-plating was done exclusive- 
ly by batteries of various kinds, but at the 
present time the dynamo has almost entirely 
superseded them, except for amateur work 
and where power is not available. 

H. H. Reama. 



Electro- Plating and Analysis of Solutions 1 

ELECTRICAL TERMS. 

Volt: A volt is the unit of electrical pres- 
sure or electro-motive force, and is used the 
same as pound pressure when applied to a 
steam boiler or water pipe. 

Ampere: An ampere is the unit of quan- 
tity, and is used to denote the amount of cur- 
rent flowing, in the same way that gallons or 
cubic feet per minute are used when applied 
to steam or water. 

Ohm or Resistance: An ohm is the unit of 
resistance and corresponds to the friction that 
exists' where water is flowing through a pipe. 
Therefore it can be readily seen that there 
exists a definite relation between the above 
electrical terms, namely: volt, ampere, and 
ohm, and a volt represents the pressure ex- 
erted by a current of electricity of one am- 
pere flowing through a resistance of one ohm. 
The electrical formula is expressed as follows : 

E 
C = — in which of course "C" is the amount 

R 
of current or amperes, — "E" is electro- 
motive force or volts, while "R" is resistance 
or ohms. Consequently we have E (volts) = 
C (amperes) X R (ohms) and R (ohms) = 
E (volts') 

C (amperes) 



2 Electro- Plating and Analysis of Solutions 

CONDUCTORS. 

It has been stated by competent and 
qualified people that by using bus-bars 
of the type shown in Fig. 1, say % x 1% 
or y% x 1U. inches will give better service than 
the ordinary round bar. This is strictly a 




Fig. 1— Rectangular Buss Bar 



matter of opinion and is still up to the man in 
charge or in ownership of the said factory or 
shop. As heretofore stated many means of 




Fig. 2— Round Buss Bar 

operating can be and are used at the present 
writing, and it is quite difficult to meet all 
requirements and all classes of trade and still 
meet the approval of the majority. Never- 
theless, facts are facts, and the above are true. 



Electro- Plating and Analysis of Solutions 3 

CLEANING CAST IRON BEFORE 
PLATING. 

Steep the work in a solution of potassium 
hydrate (caustic potash), then rinse in clean 
water, dip in sulphuric pickle, (1 gallon of 
sulphuric acid to 10 gallons water), until free 
from all scale, scour with pulverized pumice 
and tampico brush or wheel. Then rinse in 
clean water and dip in a dilute muriatic acid 
pickle, rinse in clean water, and if work is 
porous rinse in lime water (if not porous it is 
not necessary) then rinse in clean water and 
hang in plating solution. 

Some people use oxalic acid in place of 
muriatic acid (one pound of oxalic acid to 1 
gallon water is a very good solution.) 



A 1 CLEANING COMPOUND OR 
CLEANING SOLUTION. 

100 pounds alkali (potash) (potassium hydrate), 
75 " sal soda, (carbonate of sodium), 
20 " light fish oil, 
Heat at first, then add alkali and sal soda. 

1 gallon 26° ammonia, (aqua ammonia, am- 

monium hydrate), 
Y\ pound borax soap cut up in pieces. 

2 pounds cream of tartar. 



4 Electro- Plating and Analysis of Solutions 

CLEANING OF METALS BEFORE 

PLATING. 

That should not be scoured. 

The success of all kinds of electro-plating 
depends greatly upon the work being chemic- 
ally clean; that is, free from all grease and 
dirt. This especially applies to nickel-plat- 
ing, as the chemical character of a nickel solu- 
tion is such that it has no dissolving action on 
grease, etc., and the deposit will surely strip 
or peel from the greasy spots. The operation 
of cleaning the articles differ in many estab- 
lishments, but the following methods are those 
which have been found best from practical 
experience for copper, brass, britannia metal, 
tin, pewter, lead, and antimony and most any 
mixture of soft metals. Soft metals are such 
as are made from tin, lead, antimony, bismuth. 
Steep the work in a boiling solution of potash 
or lye, say 6 to 10 ounces of lye to 1 gallon 
of water. 

The solution should stand about 10° 
Baume, and be kept hot. After the work 
has been hanging in solution some time, rinse 
well in clean water. Then dip the work in a 
solution of cyanide of potassium made up say 
of Yz pound of cyanide to 1 gallon of water. 
This will remove any oxidization which may 
have formed on the work. Then rinse well in 
clean water, so that all potash and cyanide is 
thoroughly removed from the work, as none 
must on any account get into the solution. 



Electro- Plating and Analysis of Solutions 5 

Notice if the water wets the whole surface of 
the work, and runs off without running from 
some parts of the work only, as it does with 
anything that is greasy. If the work shows 
any signs of grease by the water not running 
off properly, then dip in potash and cyanide 
and rinse as before. Then hang work in solu- 
tion at once without touching the work with 
the fingers, as grease from the fingers will 
adhere to the work and cause trouble. 

Britannia metal and pewter should not be 
left long in the potash, as the solution exerts 
a solvent action on tin and its alloys. 

ELEMENTS. 

Following is given a list of all known ele- 
ments with their atomic weights as reported 
by the International Committee an Atomic 
weights. 

Atomic 
Element Symbol Weight 

Aluminum Al 27.1 

Antimony Sb 120.2 

Argon A 39.9 

Arsenic As 75.00 

Barium Ba 137.4 

Bismuth Bi 208.00 

Boron B 11.00 

Bromine Br 79.96 

Cadmium Cd 112.4 

Caesium Cs 132.9 

Calcium Ca 40.1 

Carbon C 12.00 

Cerium Ce 140.25 



6 Electro- Plating and Analysis of Solutions 

ELEMENTS. 

Atomic 
Element Symbol Weight 

Chlorine CI 35.45 

Chromium Cr 52.1 

Cobalt Co 59.00 

Columbium Cb 94.00 

Copper Cu 63.6 

Erbium E 166.00 

Europium Eu 152.00 

Fluorine F 19.00 

Gadolinium Gd 156.00 

Gallium Ga 70.00 

Germanium Ge 72.5 

Glucinum Gl 9.1 

Gold Au 197.2 

Helium He 4.00 

Hydrogen H 1.008 

Indium In 115.00 

Iodine I 126.97 

Iridium ..Ir 193.00 

Iron Fe 55.9 

Krypton Kr 81.8 

Lanthanum La 138.9 

Lead Pb 206.9 

Lithium ....Li 7.03 

Magnesium Mg 24.36 

Manganese Mn 55.00 

Mercury Hg 200.00 

Molybdenum Mo 96.00 

Neodymium Nd 143.6 

Neon Ne 20.00 

Nickel Ni 58.7 

Nitrogen N 14.01 

Osmium Os 191.00 

Oxygen O 16.00 



Electro- Plating and Analysis of Solutions \ 

ELEMENTS. 

Atomic 
Element Symbol Weight 

Palladium Pd 106.5 

Phosphorus P 31.00 

Platinum Pt 194.8 

Potassium :K 39.15 

Praseodymium Pr 140.5 

Radium Ra 225.00 

Rhodium Rh 103.00 

Rubidium Rb '. 85.5 

Ruthenium Ru 101.7 

Samarium Sm 150.3 

Scandium Sc 44.1 

Selenium . . Se 79.2 

Silicon S'i 28.4 

Silver Ag 107.93 

Sodium Na 23.05 

Strontium Sr 87.6 

Sulphur S 32.06 

Tantalum Ta 181.00 

Tellurium Te . 127.6 

Terbium Tb 159.2 

Thallium Tl 204.1 

Thorium Th 232.5 

Thulium Tu 171.00 

Tin Sn 119.00 

Titanium . . .Ti 48.1 

Tungsten W 184.00 

Uranium U 238.5 

Vanadium V 51.2 

Xenon X 128.00 

Ytterbium Yb 173.00 

Yttrium Y 89.00 

Zinc Zn 65.4 

Zirconium Zr 90.6 



8 Electro- Plating and Analysis of Solutions 

EQUATIONS. 

The following are some simple equations 
which are frequently encountered in plating 
operations. 

Hg + O = Hg O Mg + O = Mg O 

HC1 + NH 3 = NH 4 CI 
H.O + CaO = CaO., H 2 
H, S0 4 + 2KN0 3 = KoS0 4 + 2HN0 3 
2HN0 3 + Na 2 C0 3 = 2NaNO s + C0 2 + HX> 
2HC1 + Zn = ZnCl 2 + 2H 
CH 4 + 2C1 = CH 3 C1 + HC1 
Zn + H 9 S0 4 = ZnS0 4 + 2H 
Ba0 2 = BaO + O SMn0 2 = Mn 3 4 + 20 

8KC10, = 5KC10 4 + 3KC1 + 40 
With sulphur S + 20 = S0 o 
With carbon C + 20 = CCX 
With iron 3Fe + 40 = Fe 3 4 
With phosphorus 2P + 50 = PoO- 
K + H 2 = KOH + H 
Na + HX> = NaOH + H 
3Fe + 4H,0 = Fe 3 4 + 8H 
C + H = CO + 2H 
Zn + 2HC1 = ZnCl, + 2H 
Zn + H 2 S0 4 = ZnS0 4 + 2H 
Fe + 2HC1 = FeCl 2 + 2H 
Fe + H S0 4 = FeS0 4 + 2H 
CuO + 2H = H 2 + Cu 
Fe 2 O s + 6H = 2Fe + 3H 2 
Fe 3 4 + 8H = 3Fe + 4H.O 
3Fe + 4H 2 = Fe 3 4 + 8H 
Ca + 2H 2 6 = CaH 2 0„ + 2H 
Ba + 2HLO = BaHoO" 2 + 2H 
KCIO3 = KC1 + 3(5 
HoO = 2H + O CaCO s = CaO + CO. 



Electro- Plating and Analysis of Solutions 



WEIGHTS AND MEASURES. 



Linear Measurements. 

10 millimeters (mm.) = 1 centimeter (cm.) 
10 centimeters = 1 decimeter (dm.) 

10 decimeters ■= 1 meter (m.) 

Equivalent, 1 inch = 2.5 cm. (approximately) 

Square Measurements. 

100 sq. millimeters (mm 2 ) = 1 sq. centimeter 

(cm 2 ) 
100 sq. centimeters = 1 sq. decimeter (dm 2 ) 
100 sq. decimeters = 1 sq. meter (m 2 ) 

Cubic Measurements. 

1000 cu. millimeters (mm 3 ) = 1 cu. centimeter 

(ccor cm 3 ) 
1000 cu. centimeters = 1 cu. decimeter (dm 3 ) 
1000 cu. decimeters = 1 cu. meter (m 3 ) 
Equivalents, 1000 cc. = 1 liter (1 1.) 

1 1. = 1 quart (approximately) 

Conversion Table. 

1 cc. of water (S.T.P.) = 1 g. 
1 1. of water (S.T.P.) = 1 k. 
30 g. = 1 ounce (approximately) 
1 k. = 2.2 pounds (approximately) 
1 g. = 15 gr. (approximately) 
1 1. hydrogen = .09 g. (approximately) 



10 Electro- Plating and Analysis of Solutions 

Troy Weight. 

24 grains == 1 dwt. 

20 dwts. = 1 ounce. 

12 ounces = 1 pound. 

Used for weighing gold, silver and jewels. 

Apothecaries' Weight. 
20 grains = 1 scruple. 

3 scruples = 1 dram. 

8 drams = 1 ounce. 

12 ounces = 1 pound. 

The ounce and pound in this are the same as in 
Troy weight. 

Avoirdupois Weight. 
27 11-32 grains = 1 dram. 



16 drams 


= 1 ounce. 


16 ounces 


= 1 pound. 


25 pounds 


= 1 quarter. 


4 quarters 


= 1 cwt. 


2,000 pounds 


= 1 short ton 


2,240 pounds 


= 1 long ton. 


Dry 


Measure. 


2 pints 


— 1 quart. 


8 quarts 


.=' 1 peck. 


4 pecks 


= 1 bushel. 


36 bushels 


= 1 chaldron. 



Liquid Measure. 

4 gills = 1 pint. 

2 pints = 1 quart. 

31^ gallons = 1 barrel. 

2 barrels = 1 hogshead. 



Electro- Plating and Analysis of Solutions 



11 



Time Measure. 


60 seconds 


= 1 minute. 


60 minutes 


= 1 hour. 


24 hours 


= 1 day. 


7 days 


= 1 week. 


28, 29, 30, or 31 days = 


= 1 calendar month (30 ds.) 


365 days = 1 year. 




Circular Measure. 


60 seconds 


= 1 minute. 


60 minutes 


= 1 degree. 


30 degrees 


= 1 sign. 


90 degrees 


= 1 quadrant. 


4 quadrants 


— 12 signs. 


360 degrees 


= 1 circle. 


Long 


Measure. 


12 inches 


= 1 foot. 


3 feet 


= 1 yard. 


t>y 2 yards 


= 1 rod. 


40 rods 


= 1 furlong. 


8 furlongs 


= 1 statute mile. 


3 miles 


= 1 league. 


Miscellaneous. 


3 inches 


= 1 palm. 


4 inches 


= 1 hand. 


6 inches 


= 1 span. 


18 inches 


= 1 cubit. 


21.8 inches 


= 1 Bible cubit. 


%y 2 feet 


= 1 military pace. 


Weight Table. 


10 milligrams (mg.) 


= 1 centigram (eg.) 


10 centigrams 


= 1 decigram (dg.) 


10 decigrams 


= 1 gram (g.) 


1000 grams 


= 1 kilogram (k.) 



12 Electro- Plating and Analysis of Solutions 

Cloth Measure. 

%Y<\ inches = 1 nail. 

4 nails = 1 quarter. 

4 quarters = 1 yard. 

Square Measure. 

144 sq. inches = 1 sq. foot. 

9 sq. feet = 1 sq. yard. 

30^4 sq. yards = 1 sq. rod. 

40 sq. rods = 1 rood 

4 roods = 1 acre. 

640 acre's = 1 sq. mile. 

Surveyors' Measure. 

7.92 inches = 1 link. 

25 links = 1 rod. 

4 rods = 1 chain. 

10 square chains or 160 square rods = 1 acre. 
640 acres = 1 sq. mile. 
36 sq. miles (6 miles sq.) = 1 township. 

Cubic Measure. 

1,728 cubic inches = 1 cubic foot. 
27 cubic feet = 1 cubic yard. 

128 c. ft. = 1 cord (wood). 

40 cubic feet = 1 ton (shpg.) 

2,150.42 cubic inches = 1 standard bushel. 
268.8 cubic inches = 1 standard gallon. 
1 cubic foot = about four-fifths of a bushel. 

Mariners' Measure. 

6 feet = 1 fathom. 

120 fathoms = 1 cable length. 

yy 2 cable lengths = 1 mile. 
5,280 feet = 1 statute mile. 

6,085 feet = 1 nautical mile. 



Electro-Plating and Analysis of Solutions 



13 



METRIC EQUIVALENTS. 

Linear Measure. 



1 centimeter 


= 0.3937 inches. 


1 decimeter 


= 3.937 in =0.328 ft. 


1 meter 


= 39.37 in . = 1.0936 yds 


1 dekameter 


= 1.9884 rods. 


1 kilometer 


= 0.62137 mile. 


1 inch 


= 2.54 centimeters. 


1 foot 


== 3.048 decimeters. 


1 yard 


= 0.9144 meter. 


1 rod 


= 0.5029 dekameter. 


1 mile 


= 1.6093 kilometers. 




Square Measure. 


1 sq. centimeter 


= 0.1550 sq. inches. 


1 sq. decimeter 


= 0.1076 sq. feet. 


1 sq. meter 


= 1.196 sq. yards. 


1 ar 


= 3.954 sq. rd. 


1 hektar 


= 2.47 acres 


1 sq. kilometer 


= 0.386 sq. m. 


1 sq. inch 


= 6.452 sq. centimeters. 


1 sq. foot 


= 9.2903 sq. decimeters. 


1 sq. yard 


= 0.8361 sq. meter 


1 sq. rod 


= 0.8361 sq. ar 


1 acre 


= 0.4047 hektar. 


1 sq. m. 


= 2.59 sq. kilometers. 




Weights. 


1 gram 


= 0.03527 ounce. 


1 kilogram 


= 2.2046 lbs. 


1 metric ton 


= 1.1023 English ton. 


1 ounce 


= 28.85 grams. 


1 pound 


= 0.4536 kilogram. 


1 English ton 


= 0.9072 metric ton. 



14 



Electro-Plating and Analysis of Solutions 



Approximate 


Metric Equivalents. 


1 decimeter 


= 4 


inches. 


1 meter 


= 1.1 


yards. 


1 kilometer 


= H 


of mile. 


1 hektar 


= 2y 2 


acres. 


1 stere or cu. meter 


= Va 


of a cord. 


1 liter 


= 1.06 


qt. liquid. 


1 liter 


= 0.9 


qt. dry. 


1 hektoliter 


= 2^ 


bush. 


1 kilogram 


= 2% 


lbs. 


1 metric ton 


= 2,200 


lbs. 



Measure of Volume. 



1 cu. centimeter 


= 


0.061 


cu. in. 


1 cu. decimeter 


= 


0.0353 


cu. ft. 


1 cu. meter 


= 


1.308 


cu. yd. 


1 stere 


= 


0.2759 


cd. 


1 liter 


= 


0.908 


qt. dry 


1 liter 


= 


1.0567 


qt. liq. 


1 dekaliter 


= 


2.6417 


gal. 


1 dekaliter 


z= 


.135 


pks. 


1 hektoliter 


= 


2.8375 


bush. 


1 cu. inch 


= 


16.39 


cu. cent'rs 


1 cu. foot 


= 


28.317 


cu. deci'rs. 


1 cu. yard 


= 


0.7646 


cu. M'r. 


1 cord 


= 


3.624 


steres. 


1 quart dry 


= 


1.101 


liters. 


1 quart liquid 


= 


0.9463 


liter. 


1 gallon 


= 


0.3785 


dekaliter. 


1 peck 


= 


0.881 


dekaliter. 


1 bushel 


= 


0.3524 


hektoliter. 



Electro- Plating and Analysis of Solutions 15 

Electrical Requirements Necessary in 
a Plating Room. 

XN the first place it is better to buy a first 
class dynamo even though it be a little 
more expensive in the beginning, it will prove 
to be the cheapest in the end. The dynamo 
should be set up on a good solid foundation 
and as near to the tanks as convenient, and 
should be placed so that your plater will have 
easy access to all its working parts. A few 
minutes attention given to the dynamo each 
morning adds greatly to efficiency, and will 
keep commutator and brushes in good condi- 
tion. Be sure the dynamo rests firmly on its 
foundation. Great care should be taken in ad- 
justing the brushes not to have too much pres- 
sure on commutator. The brushes should not 
bear too hard on commutator, but just enough 
to insure perfect contact between brush-holder 
and rod. If commutator shows signs of 
roughness, smooth w~ith fine sand-paper, and 
lubricate with vaseline. Never use emery 
paper. The conducting bars running from the 
dynamo past the various tanks in the plating 
room should be large enough to carry all cur- 
rent that the dynamo gives, and the various 
vats can be connected by means of wires or 
rods leading from the conducting bars. Great 
care should be taken to have the wires of a 
sufficient size so as not to lose too much cur- 



16 



Electro- Plating and Analysis of Solutions 




Electro- Plating and Analysis of Solutions 



17 







.. O 

»? 

I « 
*£ 

fa <u 



rent. The current must be regulated for each 
tank by a resistance switch or rheostat con- 
nected to the positive bar and also to the posi- 
tive bar of the tank. Rheostats are put up as 



18 



Electro- Platixg and Analysis of Solutions 



near to the tank as possible, and should be 
shut off while putting- work into tank, and then 
be turned toward the strongest point until a 
suitable current is obtained. 

It is quite essential in a large plating room 
to have a voltmeter, and also an ampere meter, 




Fig. 5— Ammeter for Electro-plating Work. Manufactured by 
Weston Electric Company, Newark, N. J. 

which will show the plater the exact amount 
of current he is getting. By means of an ac- 
curate ammeter, the amount of metal actually 
deposited can be determined. 



Electro- Plating and Analysis of Solutions 19 

NICKEL PLATING. 

The solution should be made up by dissolv- 
ing % of a pound of nickel-ammonium sul- 
phate (double nickel salts) (1 gallon of 
water), which will bring the density up to 
about 6° or 7° Be, and adding a small amount 
of boric acid, making a very fine bright nickel. 
In some instances, agitated solutions are of 
great importance, for the reason that a higher 
current density may be used, and decrease the 
time, prevent pitting, and the work will 
come out just as bright as in a still solution. 

Anodes: Now as to anodes, they are very 
important in nickel solutions, owing to the 
fact that the solution does not readily dissolve 
the metal, as this action takes place only by 
the aid of the current, and as nickel sulphate 
will not conduct electricity properly, and as 
ammonium sulphate will, we have combined 
them and make the double salt, and the free 
sulphuric acid liberated by the deposition im- 
mediately passes to the opposite pole, and 
attacks the anodes. A large anode surface is 
necessary. Cast anodes are preferable, as 
rolled anodes are so hard that more current is 
required. 

Bath: The bath should be slightly acid. 
This condition can be readily told, by testing 
with litmus paper. Blue litmus paper is 
colored red by acid, and red litmus paper is 
colored blue by an alkali. Too much acid will 



20 Electro-Plating and Analysis of Solutions 




is 

8.1 

S3 

o g 

. o 

"3 b 



cause peeling, and if the bath is alkaline a 
dark deposit will be obtained. The solution 
should be kept always at 6}^ to 7° Be. 



Electro- Plating and Analysis of Solutions 21 

COPPER PLATING. 

A very fine bright deposit of copper can be 
obtained by making a solution of 

1 gallon of warm water, 

5 ounces of carbonate of copper, 
10 " cyanide of potassium, 

2 " bisulphite of soda. 




Fig. 7— Voltmeter used in Electro-plating 
Manufactured by Weston Electric Company, Newark, N. J. 



Sometimes a person may have trouble 
owing to his copper solution not depositing 
any copper. As a rule this is due to insufficient 
cyanide. As for example, if there is not 
enough cyanide in the bath, the anodes will 
become coated with a greenish coat. Remedy. 



22 Electro-Platixg and Analysis of Solutions 

add cyanide. When the bath is working prop- 
erly, there will be no traces of green upon the 
anodes, and the work hung in the tanks to be 
plated should be rapidly covered with metal. 
On the other hand when there is too much cy- 
anide in the bath, hydrogen bubbles will come 
very freely from the work to be plated. 
Remedy, add copper cyanide. 

The above solution is for ordinary work. 
Of course there are various ways of running 
a copper solution. For instance, if a copper 
solution is to be used for striking steel knives 
before silver plating them, this solution should 
be made rich with cyanide, and just enough 
carbonate of copper to deposit freely. 

To make this solution use about 

8 ounces of Cyanide of potassium. 
4 ' Carbonate of copper. 

When this solution is first tried if there is 
no deposit, add carbonate of copper slowly 
until a good deposit is obtained. If the work 
blisters by using a strong current, reduce the 
current. If it still blisters, add a little more 
cyanide. The solution should stand about 
10° Be. 

BRASS PLATING SOLUTION, 

The brass, plating solution seems to be the 
most difficult of all solutions to handle, and 
there are several ways of running a brass 
solution for various kinds of work, and if a 



Electro-Plating and Analysis of Solutions 23 

man has had a little experience in brass plating 
he will readily understand what kind of a solu- 
tion is needed for the work he is about to 
plate. In my experience I have used several 
different brass solutions, and have plated sev- 
eral kinds of metals in different lines of work, 
and I find that in plating lead work or any 
white metal, that a solution made up of about 
1 Gallon of water, 
7 Ounces of carbonate of copper, 
4 " " " " zinc, 

15 " cyanide of potassium. 

A small amount of arsenic dissolved in 
caustic soda, and a small quantity of ammonia, 
will bring very good results. 

Now in making up this solution, fill the vat 
half full of water, then take dry carbonate of 
copper and carbonate of zinc, and weigh at 
the rate of 5 to 3 parts and put in a stone 
crock. Fill the crock with water and stir all to- 
gether; then in another crock put cyanide and 
dissolve it, then take a pail and fill it half full 
of the copper and zinc solution and add the cy- 
anide solution to it, and keep stirring until 
the solution becomes clear, and then add to 
the vat. When all the metal and cyanide are 
in the vat, fill up with water, then add a small 
amount of arsenic, and then about one gallon 
of ammonia to every 50 gallons. Care should 
be taken in using the arsenic, not to add too 
much. A very small amout is sufficient, and 



24 Electro- Plating and Analysis of Solutions 

when this solution is tried if it does not work 
nice and clear, simply add a little more 
ammonia. 




Fig. 8— Rheostat 
Manufactured by Bennett-O'Connell Company, Chicago, 111. 

Now I find that on plating sheet metal work 
that I obtain far better results by using the 
following solution: 

1 Gallon of water, 
12 Ounces of carbonate of copper, 

7 " " " " zinc, 

25 " cyanide of potassium, 

A small amount of ammonia. 



Electro-Plating and Analysis of Solutions 



25 



TUMBLING BARREL PLATING. 

Tumbling barrels have almost entirely done 
away with wiring or basket plating for small 
work such as screws, collar buttons, etc., and 
at the present day they turn out this class of 

work in tumbling bar- 
rels in large quanti- 
ties and in this way 
reduce the cost to a 
much smaller figure 
than when it was done 
by the old method. 

A very good brass 
solution for tumbling- 
barrel plating is 
made as follows : 
Carbonate of cop- 
per 12 oz. 

Carbonate of zinc 
6oz. 

Cyanide of potas- 
sium . . . .20 oz. 
Water .... 1 gal. 

Ammonia and 
arsenic may be 

Fig. 9— "None Such" Electro-plating Barrel 

Manufactured by Rockhill & Vietor pn r1f»nn<5 it- 

New York CU UC P UML - 




26 Electro- Plating and Analysis of Solutions 

ARGENT IVORY OR SILVER WHITE. 

This is an exceptionally fine white finish, 
burnished on certain parts, and is produced in 
'the silver solution by running the work just 
long enough to get a dead white, and rinsing 
in cold and hot water, and then in cold again, 
and dry in soap suds or alcohol, and then 
burnish using Ivcry Soap for the burnishing. 
In this way one is not so liable to stain the 
work, or burnish dry, which in some cases is 
preferable as this finish stains very easily. 
This white finish should be lacquered with a 
pure White Celluloid Lacquer. 




Fig. 10— "None Such" Carboy Rocker 

"Beginning to Pour" 

Manufactured by Rockhill & Vietor, New York 



OLD IVORY FINISH. 

This is a beautiful finish, and can be pro- 
duced in several ways. One can get a very 
fine finish by using White Enamel Lacquer 



Electro- Plating and Analysis of Solutions 27 

and spraying it on the work, and when dry ap- 
ply with a camels hair brush, burnt umber 
ground with oil and thinned with turpentine 
until the shade desired is obtained. A small 
amount of burnt umber to about 6 to 8 ounces 
of turpentine will give a fine tan color, which 
is a very fine color to apply on the white. 
Rub off with turpentine with a small piece of 
felt or chamois. A still better way to produce 
this Old Ivory is to produce the white in the 
silver solution, run the work just long enough 
to get a dead white, and then rinse off in cold 
and hot water, and then in cold water, and 
then dry in alcohol or soap suds and lacquer. 
Apply burnt umber as before. 

For the cheap class of work the cost of this 
finish can be reduced by first running the work 
in an acid copper solution for about y 2 hour 
which will give a dead finish. Then silver 
plate. In this way the dead white is produced 
m about half the time in silver solution, thus 
saving silver. 

SILVER PLATING CASKET HARD- 
WARE. 

In presenting this subject, I desire to illus- 
trate the handling of this line of work from 
the stringing or racking up to the buffing de- 
partment. 

The work is first wired or racked up, then it 
is dipped in the potash and rinsed off in clean 
water, nickel plated for about five minutes, 



28 Electro-Plating and Analysis of Solutions 

rinsed in clean water, put into the silver strike 
solution for a minute or two, then into the 
bright silver solution, where it is usually run 
for about five minutes. This class of work 
must come out of the silver solution bright 
and clear, and without stain, as some of the 
cheap w^ork goes through wnthout any buffing, 
and the work that is to be buffed has to be 
done simply by color buffing. When the work 
comes out of the silver solution it should be 
rinsed in cold water, and then in hot water, 
and then hung in an oven at 150 to 200° F. 
until thoroughly dry. It is then ready for 
buffing. 

The potash for this class of Avork should 
stand about 5 Be, and not any higher, as the 
work must not stain when potashing. The 
nickel solution should be made of J4 pound 
of double nickel salts to a gallon of water, and 
should stand about 6 to 7 Be. A small amount 
of table salt added to this solution occasionally 
will whiten the deposit. The silver strike 
solution should be made up of about 10 ounces 
of cyanide of potassium to the gallon, and y 2 
ounce of silver chloride to a gallon of water. 
The silver solution should contain 2 ounces of 
silver chloride and about 12 ounces of cyanide 
of potassium per gallon of water, and add 
bisulphide of carbon in the usual manner to 
brighten the deposit. Care should be taken 
in adding this brightener, as too much will 
give very bad results. 



Electro-Plating and Analysis of Solutions 



29 




Fig. 11— "None Such" Plating Barrel Double Type 
Manufactured by Rockhill & Vietor, New York 



30 Electro- Plating and Analysis of Solutions 

SILVER PLATING STEEL KNIVES. 

The knives are first placed in a basket, and 
then washed in benzine and shaken through 
sawdust which will remove oil, and potash in 
the usual way. Potash should stand about 15 
Be. After taking- out of potash, rinse in clean 
water and place in carbonate of soda solution 
to prevent rust, and scour with fine pumice, 
rinse in clean water and rack up. Then dip in 
dilute sulphuric acid dip in proportion of 1 
part of acid to 8 parts of water, then rinse in 
clean water and hang into a steel strike. The 
steel strike is made up of 

Carbonate of copper. 10 Grains. 

Chloride of silver... 5 

Cyanide of potassiumlO Ounces. 

Water 1 Gallon. 

Use copper anode 2x8 inches in cloth bag. 
Silver 1 inch square. 

It is advisable at the end of each week to 
take out about 1 gallon of the strike solution 
and add about 1 quart of silver solution and 
cyanide enough to keep the solution standing 
10 Be. Never add any copper to the strike 
after first making, as all the copper required is 
obtained from the anode. After striking the 
knives in steel strike, they should be rinsed 
in clean water, and struck up in the regular 
silver strike, and from there into silver solu- 
tion. The silver solution should always stand 
about 15° to 18° Be, and have 4 to 4^2 ounces 
of chloride of silver per gallon, and 15 to 20 



Electro- Plating and Analysis of Solutions 31 

ounces of cyanide of potassium per gallon. It 
is best to keep the knives in motion while 
plating by means of a swing frame attached 
to the negative pole, which is the plating pole. 
A scale attachment which will register the 
amount of silver being deposited can also be 
obtained. 

SILVER PLATING HOLLOW WARE. 
Brass, Copper, or German Silver. 

The work is first dipped in potash standing 
about 15 Be, rinsed in clean water, scoured 
with fine pumice on a tampico brush or wheel, 
allowing a steady drip of water to flow on the 
wheel while work is being scoured, so as to 
keep work wet, then sponge off" thoroughly in 
clean water and hook or wire up, when it is 
ready for plating. The work is then hung in 
a clean water vat until the plater is ready to 
handle it. On removal, dip in potash stand- 
ing about 10 Be, rinse in clean water and dip in 
mercury dip, rinse in clean water, and dip in 
potash, and then in a weak cyanide of 
potassium dip, and from this into silver strike 
solution, where it is struck up for a few min- 
utes, and then into silver solution where it 
remains until the desired amount of silver is 
deposited. This method is for burnish or satin 
finished work. 

Now if the work is only to be buff finished, 
a different method should be used in cleaning, 
as this class of work should come out of solu- 



32 Electro- Plating and Analysis of Solutions 

tion bright and without stain, as we only burn- 
ish parts that cannot be readily reached by 
the buff. Therefore, we use a solution of 
Kalye about 8 ounces to a gallon of hot water. 
Place work in Kalye solution a couple of min- 
utes, wash off with a cotton flannel brush, 
scour only such parts as inside of tea pots, 
or under handle, etc., and then plate in a bright 
silver solution. For satin finish or burnished 
work it is best to use a solution composed of 

Chloride of silver. . . 3 to 4 Ounces. 

Cyanide of potassiuml5 to 18 

Water 1 Gallon. 

Bright silver solution should contain 

Chloride of silver. . . 2 to 2^/2 Ounces. 

Cyanide of potassiuml2 to 15 

AVater 1 Gallon. 

Bisulphide of carbon should be added in the 

usual manner. 

Silver Plating Lead or Spelter Articles. 

In my experience, I have found that the 
best results in this line of work can be ob- 
tained by first washing the articles in benzine 
and then shaking through sawdust. They 
should then be hooked or racked up and 
dipped through potash, rinsed in clean water, 
strike in cyanide copper solution for a couple 
of minutes, and nickel plate about y 2 hour. 
Then rinse in clean water, potash and rinse 
again and then place in silver strike solution, 
and plate in the ordinary silver solution until 



Electro- Plating and Analysis of Solutions 33 

the desired amount of silver is deposited. The 
reason for nickel plating is only to save silver, 
for instance, when you relieve an article for 
French Gray finish, you are liable to cut 
through on some little part, and if you have a 
nickel base under the silver, it in most cases 
would not be noticed. 



ROSE GOLD. 

I will now make a few remarks on the rose 
gold finish, which is a beautiful finish on al- 
most any kind of work. There are several 
ways of producing this finish, for instance, if 
you want a fine rose finish on high class jewel- 
ry, you have to produce your smut by the use 
of an old gold solution, to which you may add 
a small amount of caustic potash, and use 
carbon anodes. I have found that adding car- 
bonate of copper taken up with yellow prus- 
siate of potassium in small quantities will give 
you a very fine red rose. Run work in this 
solution for a couple of minutes, then rinse 
in a weak cyanide of potassium dip, then re- 
lieve with bi-carbonate of soda, and then run 
into a roman gold solution, which consists of 

2 Ounces of C. P. cyanide of potassium, 

1 Gallon of water, 

5 Pennyweights of fulminate of gold. 

For cheap classes of work we can produce 

a rose finish which is very inexpensive, and 

which is also a very nice finish' by producing 

the smut in an acid copper solution, and then 



34 Electro- Plating and Analysis of Solutions 

relieving with bi-carbonate of soda, and gold 
plating in a roman gold solution. I have also 
had pretty good success by using a dip gold 
solution made up of 

1 Gallon of warm water, 

5 Pennyweights fulminate of gold, 

2 Ounces C. P. cyanide of potassium, 
2 Ounces phosphate of soda, 

1 Stick caustic potash. 



GILDING INSIDE OF SPOONHOLD- 
ERS, CUPS, CREAM PITCHERS, ETC. 

Gilding Solution: 

Water 1 Gallon. 

Cyanide of potassium 8 Ounces. 

Fulminate of gold. . .10 Pennyweights. 

Fill cup with gold solution and hang anode 
in cup until you get desired color. Now in 
case you have a cream pitcher with a lip on it 
to gold line so that when you fill cup with 
solution it does not cover all parts that are to 
be gilded, the proper way to gild such a piece 
of work is to have a tight rubber band to place 
around the top so as to hold solution up to 
highest point in order to gild the lip. Or use 
wax which by some silver concerns is called 
"Gilders Wax." This wax should be heated 
in warm water until it becomes soft, so that it 
can be stretched out in any length or width 
desired, and place on work while warm. In 
this way you can gild any piece of work no 
matter what shape it may be. For instance, 



Electro- Plating and Analysis of Solutions 35 

if you have 25 cups with an uneven surface 
on top, you can heat a lump of this wax, 
enough to place over the lip of these 25 cups, 
and by the time you get wax on all of them, 
the first will be cool enough to proceed with 
the gilding. Then when all are gilded' the 
wax should be taken off by placing in warm 
water, when it can be easily removed. Care 
should be taken not to have the water too 
warm. 

Gilders Wax : 

White Wax 1 Pound. 

Rosen 2 Pounds. 

Mix by heat. 



GOLD PLATING 14 OR 18 KARAT 
COLOR ON JEWELRY. 

In my experience I have found that there 
is but one way to make these solutions, and 
obtain first class results, and that is to pur- 
chase a 14 Karat anode, and run the gold into 
a cyanide solution by using a porous cup until 
you have drawn off about 10 pennyweights 
of your anode into 1 gallon of C. P. cyanide 
of potassium solution. Have the solution stand 
about 6° Be. In this way you get a beautiful 
14 to 18 Karat color, which will run very 
even. The richer the solution in gold, the 
richer color you will get. Therefore, when 
your solution is first made up with 10 penny- 
weights to the gallon, you will get about an 



36 



Electro- Plating and Analysis of Solutions 



18 Karat color and as you use the solution 
it will go down to a 14 Karat, and you can get 
about any shade from a copper color to al- 
most a 22 Karat in this way. 




Fig. 12— "None Such" Carboy Rocker 

"Getting Out the Last Drops" 

Manufactured by Rockhill & Vietor, New York 



DARK BROWN ON COPPER OR BRASS. 

Water 1 Gallon. 

Chlorate of potash.. 3 Ounces. 
Sulphate of copper.'. 3 " 
Hyposulphite of soda 3 
Acetate of copper. . . 3 

Use hot. In some cases Sulphate of nickel 
may be added. 



Electro- Plating and Analysis of Solutions 37 

BRIGHT FOR SILVER. 

Chloroform or ether. 2 Ounces. 

Bisulphide of carbon 4 

Silver solution 2 Quarts. 



GREEN GOLD. 

A very fine green gold color can be pro- 
duced in a solution of 

10 Gallons of water, 
10 Pennyweights of fulminate of gold, 
20 Ounces C. P. cyanide of potassium, 
3 Pennyweights chloride of silver, 
2 Grains acetate of lead. 

Ormulu Gold Finish on Lead Work. 

The first thing to do is to see that your 
work is properly cleaned, and a very good 
way to clean this kind of work is to wash with 
benzine and dry out with sawdust ; then wire 
or rack up your work, dip through potash and 
rinse in clean water, and hang into bright 
cyanide copper solution until coated all over 
with copper, then hang into your acid copper 
solution for from one to two hours according 
to the class of work you are doing; then dip 
into a bright dip composed of 

\y 2 parts of oil of vitrol, 

1 part of nitric acid. 

Then rinse off thoroughly in clean water' 
and hang in brass solution until you obtain a 
nice yellow brass. About 2 or 3 minutes is 



38 Electro-Platixg and Analysis of Solutions 

sufficient. Then gold plate in salt water gold 
solution. 

The brass solution for this class of work 
should be made up as follows : 
1 Gallon of water, 
12 Ounces of carbonate of copper, 

6 " " «■ "- zinc, 

25 " " cyanide of potassium. 
A small amount of ammonia. 
The salt water gold solution should be 
made up of 

8 Ounces yellow ferrocyanide (yellow 
prussiate of potassium), 
24 Ounces carbonate of sodium, 
16 phosphate of sodium. 

3 Pennyweights fulminate of gold, 
1 Gallon of water. 

In setting up this solution, you should get 
a red porous jar, and a copper kettle ; place the 
jar in the kettle and place a piece of sheet zinc 
around the porous jar. The sheet zinc should 
be about y 2 inch thick. A copper rod should 
be attached to the zinc with rivets so as to get 
a good connection. Stand the porous jar and 
zinc on either wood or glass in the bottom 
of the copper kettle. The salt water which is 
used to form battery should be made from 
rock salt (which is very cheap), and a little 
salammoniac, and should stand about 12° to 
15° Be, and should be heated with a copper 
coil. 

Be sure and use copper or brass coil 



Electro-Plating and Analysis of Solutions 



39 



TO HAN 6 WORK 
FROM 



SALT SOLUTION 

made of rock 
salt to register 

15* 



GOLD 
SOLUTION 



TEMP or 
SOLUTION 
/7S° 




PORUS POT 



izznzmzzzzzzzzzzzzzzmzzzzzzmzzzzznnti zzz^ 

Fig. 13— The Outfit for Salt Water Gilding 



*/s Copper Rod 



Zinc 

'/ s THICK 



COPPER POT 



n 5T£Ar1 COIL 

or coppcr 

at tot torn of 
copper pot- 



SOME TALK ON LACQUER. 

First be sure the work to be lacquered has 
been thoroughly cleaned. Then a room free 
from dust should be fitted up with an oven 



40 Electro- Plating and Analysis of Solutions 

heated to 140° F. and supplied with a chimney 
or some means of carrying off the fumes of 
the lacquer, which are very disagreeable. 

For dip lacquering the lacquer is placed in 
an iron enameled vat. The articles perfectly 
clean are hung on hooks and dipped into the 
vat and held up for a few minutes to allow the 
superfluous liquid to run off. Then they are 
hung up to dry in the oven. Dip lacquers are 
best thinned at night which will allow time to 
thoroughly blend. It is impossible to use a 
single solvent for an all around lacquer. Dip 
work requires one rate of evaporation, and 
spray work another rate. This is regulated by 
the solvents used, and the proportions of each - 
and only experience can teacfr it. Brush lac- 
quer is the same as dip lacquer except that it 
should be used with a thicker body so it will 
spread well under the brush. A fitch or camels 
hair brush should be used. 

The proper preparation of lacquer solvents 
calls for the highest degree of skill and care. 
The solvents must be prepared water white 
and free from water and acid. Lacquer will 
attract moisture from the air in a damp room, 
and thus cause considerable trouble. Lac- 
quered work which is thoroughly dried in an 
oven will be softened up again if a lot of new- 
ly lacquered work is put in with it. 

For work that requires a heavy coat of high 
gloss lacquer, additions of various gums are 



Electro- Plating and Analysis of Solutions 41 



made, some for hardness, some for gloss, and 
some for adhesion. Each in its proper pro- 
portion, and each with a certain amount of 
proper solvent to carry it. Some solvents pre- 
cipitate some gums, and their relative evapor- 
ating points are to be considered. Gum lac- 




Fig. 14— Rheostat and Wattmeter 

Manufactured by Western Electric Company 

New York and Chicago 

quers unless a very heavy coat is required 
may be thinned out with three or four parts 
of thinner. If heavy coats are required they 
should be dried with considerable heat to 
harden them. A thoughtful, careful workman 
will obtain far better results with a fair grade 
of lacquer, than a careless workman will with 
the best grade. 



THE USE OF WATER DIP LACQUERS. 

This name is applied for the reason that af- 
ter the article has been plated and without 
drying' it can be dipped into the lacquer with- 



42 Electro- Plating and Analysis of Solutions 

out in any way injuring the finish. These lac- 
quers are very beneficial for bright dipped 
finishes that are used in basket work. Also 
mat finish work on sheet brass, etc. Such 
work would tarnish at once if dried and then 
lacquered, and for this reason must be lac- 
quered as soon as the dipping method is over. 

For instance, sheet brass that is to be mat 
finished and dipped through bright dip 
often causes lots of trouble if you stop to dry 
it before lacquering. On the other hand if 
you dip this work through hot soap water 
and clean hot water, and then dip into lacquer, 
you will have no trouble whatever. The dip 
lacquer for this class of work should be used 
very thin so it will run off without leaving a 
drip. I have lacquered thousands of pieces of 
this class of work in this way, and have had 
very good results. 

The water should be removed every day 
either by syphon, or by means of a faucet at 
the bottom of tank. A wire screen nickel 
plated with a coarse mesh should be placed a 
few inches from the bottom of lacquer tank. 
All dirt, etc., carried into the lacquer will sift 
through the screen, and can be drawn off 
with the water. 



BURNISHING WITH STEEL BALLS. 

This method of burnishing small metal ar- 
ticles in tumbling barrels is a method of mix- 
ing articles such as buckles, chains, collar but- 



Electro-Platixg axd Analysis of Solutions 



43 



tons, etc., with steel balls in the proper pro- 
portion and rolling together in a soap solu- 
tion. The balls required must be hard and 



BEARINGS RING OILED 

/AND BRONZE BUSHED 

BRASS COVER y FRICTION CLUTCH 



WATER 




Fig. 15— Steel Ball Burnishing Barrel (Single) 

The cut shows barrel in position for working. 

Made by The Baird Machine Company, Bridgeport, Conn. 

smooth. Any non-alkali soap will do. Small 
articles can be burnished and handled in large 
quantities in this way at a very small expense. 



44 Electro-Plating and Analysis of Solutions 



I have burnished rose and green gold 
buckles in this way when I only wanted them 
to be burnished on the high lights - and by 
tumbling them thirty minutes I got out very 



%- WATER 



FRICTION CLUTCH PULLEYS 







HARDWOOD LINING 1 
SRASS COVER 



303-2 



Fig. 16— Double Burnishing Barrel for use with steel balls 

Manufactured by The Baird Machine Company, Bridgeport, Conn. 

The cut shows one Barrel horizontal and the other in position for dumping 



near the same class of work as I would had 
they been hand burnished, and the cost when 
the work is handled in this way is very small. 
Care should be taken not to allow the steel 
balls to become rusty. 



Electro- Plating and Analysis of Solutions 



45 



CHEMICALS USED 

Sulphuric Acid, 
Nitric Acid, 
Muriatic Acid, 
Citric Acid, 
Boracic Acid, 
Arsenious Acid, 
Hydrofluoric Acid, 
Bichromate of Potash, 
Caustic Potash or Potas- 
sium Hydrate, 
Cyanide of Potassium, 
" Silver, 
" Copper, 
" Zinc, 
Sodium Carbonate, 
Bicarbonate, 
Bisulphite, 
Hyposulphite, 
Nitrate, 
Phosphate, 
Chloride, or 
Common Salt, 
Sodium Cyanide, 
Barium Sulphide, 
Ammonium " 
Hydrosulphuret Am- 
monium, 
Ammonium Chloride, 
Hydrate, 
Yellow Prussiate of Pot- 
ash, or 
Potassium Ferrocyanide 
Sodium 
Barium 



IN PLATING ROOM. 

Acetic Acid, 

Ammonia, 

Caustic Soda or Sodium 

Hydrate, 
Potassium Sulphuret, 
Copper Chloride, 
Carbonate, 
Sulphate, 
Acetate, 
Nitrate, 
Zinc Carbonate, 
" Sulphate, 
" Chloride, 
Nickel Carbonate, 
Sulphate, 
" Chloride, 
" Ammonium Sul- 
phate, 
Iron Sulphate, 
" Chloride, 
Sesquichloride of Iron, 
Nitrate of Tin, 
Tin Chloride, or Muriate 

of Tin, 
Gold Chloride, 
Silver 
Platinum " 
Silver Nitrate, 
Lead 

Acetate, 
Lye or Potash, 
Kalye, 
Calcium Choride. 



46 



Electro- Plating and Analysis of Solutions 



THE USES OF AIR BRUSHES. 

The most up-to-date method of lacquering 
at the present time seems to be with the air 
brush called the "Sprayer," which is operated 
by compressed air, and everything from the 
largest to the smallest object can be lacquered 
or painted by means of this "Sprayer." 

There are all styles of sprayers, some for 
lacquers and some for enamels, etc., and any 




Fig. 17— Sprayers and Air Filter 
Made by Eureka Pneumatic Spray Co., New York 

number of colors can be blended together by 
use of the air brush. This method is far su- 
perior to the old way of using a camels hail 
brush. The lacquer or enamels spread better 
and you can obtain a smoother surface. It 
also saves labor, as more work can be turned 
out in this way. Four or five pieces of work 
can be turned out with the spray while you 
are doing one with a brush, and at the same 
time you have better results. It is a very 



Electro-Plating and Analysis of Solutions 47 

good idea to use a hood, paint receiver and 
exhaust fan in connection with the "Sprayer' 1 
to remove the vapors which may arise. A 
pressure regulator and filter are also bene- 
ficial for fine work. 



FORMULAS. 

Gun Metal Finish. 

On dip brass, copper, german silver, etc., or 
on any metal : 

Make a saturated solution of cyanide of po- 
tassium and arsenic, and use iron anodes and 
ordinary current. 

To make this solution, boil the arsenic and 
cyanide together in about 2 gallons of watei 
to 2 pounds of cyanide and 1 pound of arsenic 
which will when dissolved, be about saturated 
If not, add a little more arsenic. Do not in- 
hale the fumes as they are very poisonous. 
Acid Copper Solution: 

Water 1 Gallon. 

Sulphate of copper. .32 Ounces. 

Sulphuric acid 2 " 

Steel Color on Brass. 

Muriatic acid 1 Quart. 

Iron filings or chips. 1 Handful. 
White arsenic ...... 1 Tablespoonful. 

Water • 1 Gallon. 

Use hot. 



48 Electro-Plating and Analysis of Solutions 

FORMULAS. 

Dark Brown Drab on Copper. 

Sulpho Cyanide of 

potash . 2 Pennyweights, 

Nitrate of iron 5 

Water 1 Gallon. 

Red Copper Solution: 

Water 75 Gallons. 

Prepared red copper. 10 Pounds. 
Cyanide of potassiuml2 
Bisulphite of soda. . . 10 

Brass Solution: 

Carbonate of copper. 10 Ounces. 

" zinc . . 5 
Bisulphite of soda.. 10 
Cyanide of potassium30 

Water 5 Gallons. 

A small amount of ammonia and arsenic. 

Cyanide Copper Solution: 

Carbonate of copper. 5 Ounces. 
Bisulphite of soda. . . 2 
Cyanide of potassiumlO 
Water 1 Gallon. 

Royal Copper: 

Red lead 1 Pound. 

Banner lye 2 

Boil above 20 minutes in 1 gallon of water 
and add it to 10 gallons of water. Use copper 
anode. Rinse and heat until work becomes a 
cherry red, and develop color by buffing. Use 
a hard metal, copper preferred. 



Electro- Plating and Analysis of Solutions 49 

FORMULAS. 

Tin Solution: 

Muriate of tin 6 Ounces. 

Phosphate of soda. . . 6 

Acetic acid 2 

Water 1 Gallon. 

Use pure tin anode and low voltage. 
Acetic acid hardens deposit. 

Galvanizing Solution: 

Water 1 Gallon. 

Sulphate of zinc... 2 Pounds. 

" " alum'm \y 2 Ounces.. 
Zinc anodes. 

Strip for Brass, Copper or German Silver : 

Oil of vitriol 5 Gallons. 

Nitric acid 10 Ounces. 

Use hot and remove work as soon as strip- 
ped. When acid is saturated, dilute six times 
its volume with water, and precipitate with 
salt water. 

Gold Precipitate: 

After cutting gold with aqua regia, precipi- 
tate with aqua ammonia, (aqua regia is) 

Nitric acid 1 part. 

Muriatic acid 3 " 

To Dissolve Arsenic : 

Arsenic can be dissovlved in small quanti- 
ties in the following alkalies and acids, readily 
if hot, and slowlv if cold: 



50 Electro-Plating and Analysis of Solutions 

FORMULAS. 

Nitric acid Ammonia 

Sulphuric acid Cyanide of potassium 

Acetic acid Caustic potash 

Muriatic acid, Etc. Carbonate of soda, 

Banner lye, etc. 

Hydrosulphuret of Potash: 

Caustic potash 8 Ounces. 

Pulverized sulphur.. 16 

Water 1 Quart. 

Boil one hour. After cooling, filter and use 
the clear liquid only. Add warm water, as it 
boils away. It will turn a deep red color. 

Quick Electrotype: 

Fine copper bronze 

powder 1 Ounce. 

Plumbago 1 

Rub above mixture on cast until a fine 
surface is presented, and plate in acid copper 
solution. 

Bright Pickle for Iron: 

Water 1 Gallon. 

Sulphuric acid 12 Ounces. 

Zinc 1 Ounce. 

Nitric acid 5 Ounces. 

Black Nickel Solution : 

Take (10) gallons of regular nickel solution 
(double sulphate of nickel and ammonia) 
standing 6° Be, and add (1) pound sulpho- 
cyanide of potassium and half a pound (Yi 
lb.) C. P. sulphate of zinc. Use old anodes 



Electro- Plating and Analysis of Solutions 51 

FORMULAS. 

and a current of about fi volts. Have the 
solution decidedly alkaline with ammonia. 
The zinc sulphate can be precipitated with sal 
soda and washed thoroughly, then dissolved in 
strong ammonia. The latter method will 
make the solution sufficiently alkaline. A 
small amount of aluminum sulphate added to 
this solution will improve it. 

Gold Strip: 

Sulphuric acid C. P. . . 1 Pound. 
Hydrochloric acid C. P. 2-2/3 Ounces. 

Nitric acid 40° Be 1% Ounces. 

Keep free from water. 

Soldering Acid: 

Cut zinc with muriatic acid to saturation, 
and evaporate to 1/3 by boiling, and allow to 
cool, and then add an equal volume of satur- 
ated sal ammoniac solution, and add about 
10% crude glycerine. The boiling prevents 
sputtering when using. The glycerine pre- 
vents discoloration of work. 

Green Gold Solution: 

Water 1 Gallon. 

Gold as fulminate .... 4 Pennyweights. 

Nitrate of silver 1 Pennyweight. 

Cyanide 1 Ounce. 

Blue Oxidize on any Metal: 

Nitrate of lead 4 Ounces. 

Nitrate of iron 2 Ounces. 



52 Electro- Plating and Analysis of Solutions 

FORMULAS. 

Hyposulphite of soda.. 16 Ounces. 

Water 5 Gallons. 

Use hot. 

Blue Color on Steel: 

Heat steel to straw color and plunge into 
common machine oil. The work will take on 
a beautiful blue color. 

Flux for Melting Silver: 

Bicarbonate of soda. 1 Pound. 

Cream of tartar 1% " 

Silver 1 

Dip Gold Solution: 

Water 1 Gallon. 

Yellow prussiate of pot- 
ash 12 Ounces. 

Phosphate of soda ... .10 Ounces. 
Sesquichloride of iron. . 2 Ounces. 
Fulminate of gold .... 5 Pennyweights. 

Solution must be kept in iron kettle and boil- 
ing when in use. 

Verde Green Solution: 

Water 3 Quarts. 

Chloride of calcium... 4 Ounces. 
Chloride of ammonia. . 4 Ounces. 

Nitrate of copper 4 Ounces. 

Brush on work and stipple. 

Acid Dip for Mat Finish on Brass : 

Nitric acid 1 Part. 

Oil of vitriol 2 Parts. 



Electro- Plating and Analysis of Solutions 53 

FORMULAS. 

Add Sulphate of zinc to full saturation. If mat 
finish is too coarse, add more oil of vitrol, if too 
fine, add nitric. Use hot and keep water out of 
dip as much as possible. 
Fine Brown Bronze on Copper: 

Nickel-ammonium sul- 
phate (Double nickel 
salts) 12 Ounces. 

Copper sulphate 2 Ounces. 

Water 2 Gallons. 

Use hot. Dip work in solution two or three 
minutes, take out, rinse in clean water, scratch 
brush with dry brush. If not the color desired, 
repeat as before. 

Barbadienne Bronze : 

First, plate object brass, then black nickel. 

Second, put on a mixture of sanguine and 
black lead, equal parts, and enough gum arabic 
to make it stick, say about a wineglass full 
of gum arabic to a pint of water, and enough 
of water to make a very thin mixture. 

Third, take equal parts of sanguine and pale 
gold bronze, mix very fine by grinding. If 
that does not give the desired shade add more 
of either color and nothing else. Use good 
varnish relief as for any bronze. 
Flux to Clear Chloride of Silver of Chlorine: 

Add to chloride of silver in crucible before 
melting, 40% of calcined soda. Calcined soda 
is made by heating sal soda on a hot surface 
until it is dry, and in a fine powdery form. 



54 Electro-Plating and Analysis of Solutions 

FORMULAS. 
To Crystallize Tin : 

Bring the tin article to a straw color by 
heating with blow pipe, and at once spray 
with cool water, and then plunge it into dilute 
sulphuric acid, which will bring out the 
crystals. 

A Simple Method for Testing Silver Solution 
for Silver: 

Take 4 ounces of silver solution to be tested, 
and precipitate with hydrochloric acid. If 
copper be present, it can be cut out easily with 
nitric acid. The nitric will not cut the silver 
After the silver has gone to the bottom, draw 
off the fluid and place a small piece of zinc in 
the silver, which will with the acid or a 
few drops of sulphuric acid, drive out all 
chlorine and cyanogen, leaving it a dark col- 
ored pure silver' which must be dried and 
weighed, which will give the true amount of 
silver per gallon of solution by multiplying 
by 32 the amount of silver found in 4 ounces 
of solution, as there are 12S ounces to a gal- 
lon, and we take 4 ounces of solution, so we 
multiply by 32 which gives the number of 
ounces per gallon. 

Note: This method with proper manipula- 
tion will give pretty near perfect results. 



Electro-Plating and Analysis of Solutions 55 

FORMULAS. 

To detect Iron in Sulphate of Copper : 

Dissolve sulphate of copper with ammonia 
to excess, which will redissolve the copper, 
and if iron be present it will remain at the 
bottom as hydrate of iron. 
Paint for Sectional Gold : 

Take gumquac and break with a hammer 
until it is in powder form, and then dissolve in 
wood alcohol and let stand 24 hours. Then 
strain through cheese cloth, and add any de- 
sired aniline color. Remove with lye or 
potash. 

Another very good stop-off is 

Collodion 1 Part. 

Lacquer 1 Part. 

Remove with lacquer thinner. 
Terra Cotta Bronze: 

Red sulphide of arsenic. % Ounce. 

Pearl ash 6 Ounces. 

Water 1 Gallon. 

Sulphuret of potash ... 3 Pennyweights. 
Use boiling hot. 
Jet Black on Copper. 

Water 3 Gallons. 

Pulverized sulphur .... 9 Ounces. 

Caustic Potash 1 Pound. 

Boil until sulphur is all dissolved, then filter 
and add to 20 gallons of water. Use cold on 
copper, and scratch brush work before immer- 
sion. Finish on soft rag wheel with kerosene 
and rouge. 



56 Electro- Plating and Analysis of Solutions 

FORMULAS. 

Silver Solder: 

Sterling silver 40 Parts. 

Brass " 30y 2 " 

Bronze Solution: 

Water 1 Gallon. 

Cyanide of potassium. . 6 Ounces. 

Bisulphite of soda 2 Ounces. 

Carbonate of copper . . 4 Ounces. 

Chloride of tin % Ounce. 

Use bronze anodes. 
Black Nickel Solution: 

Water 1 Gallon. 

Nickel-ammonium sul- 
phate (Double nickel 
salts) 12 Ounces. 

Sulpho cyan potash ... 3 Ounces. 

Carbonate of copper. . . 2 Ounces. 

White arsenic 2 Ounces. 

Dip Silver Solution: 

Water 1 Gallon. 

Cyanide of potassium. . 2 Pounds. 

Caustic potash y 2 Pound. 

Chloride of silver 1 Ounce. 

Stir well and use hot. 
Royal Copper Solution: 

Red lead i/ 2 . Pound. 

Caustic stick potash . .A/ 2 . Pound. 

Water 5 Gallons. 

Use pure lead anodes. 

Note: Copper plate work and then run in 
above solution for a couple of minutes, and then 
heat with blow-pipe flame and buff with red 
rouge. 



Electro- Plating and Analysis of Solutions 57 

FORMULAS. 

Black Nickel Smut for French Grey : 

Oxide of nickel 5 Pounds. 

Carbonate of copper. . . 1 Pound. 

Sal soda 100 Pounds. 

Water 150 Gallons. 

Carbonate of ammonia. 5 Pounds. 

Dissolve the copper and nickel in the ammonia. 

Verde Antique Paint. 

Chrome green, 

yellow, 
Zinc white, 

A very little yellow ocher. Mixed to de- 
sired consistency with turpentine. 

Dip Black on Brass. 

Water 1 Gallon. 

Carbonate of soda 4 Ounces. 

Carbonate of copper . . 1 Pound. 

Ammonia 1 Quart. 

Use hot or cold. 

Crystallized Tin: 

Dip tin goods in a hot solution of water and 
sesquichloride of iron. 

To Separate Silver Metal from Copper: 

Cut the combination metals with nitric acid, 
and then precipitate with hydrochloric acid, 
which will throw the silver to the bottom as 
chloride, and hold the copper in the solution 
as chloride. 



58 Electro-Plating and Analysis of Solutions 

FORMULAS. 

To Recover Gold from an Old Solution: 

Place a quantity of scrap turnings or filings 
of zinc in the solution which will collect all 
the gold, after which draw off the solution, and 
then cut the zinc with hydrochloric acid, leav- 
ing the gold at. the bottom. 

Note: Cyanide of silver is not soluble in ni- 
tric acid unless heated. Cyanide of copper is 
soluble in nitric acid cold or hot. 

To remove fire stain from Sterling Silver : 

Nitric acid 1 Part. 

Water 1 " 

Use hot. 

To strip Silver from Steel: 

Water 1 Gallon. 

Cyanide of potassium. . 8 Ounces. 
Chloride of silver .... y 2 . Ounce. 
Use reverse current, 

Stop-Off or Paint for Etching : 

Virgin rubber dissolved with benzine. Add 
a small amount, say J4 ounce of asphaltum to 
a tablespoonful of virgin rubber. Cut the as- 
phaltum with turpentine, and add the rubber 
when dissolved to the asphaltum. This is 
strictly acid proof. 



Electro-Plating and Analysis of Solutions 59 

FORMULAS. 

Color Mixing Paints, Inks, etc. 
Red and black make brown, 
Lake and white make rose, 
White and brown make chestnut, 
White, blue and lake make purple, 
Blue and lead color make pearl, 
White and carmine make pink, 
Indigo and lamp black make silver gray, 
White and lamp black make lead color, 
Black and Venetian red make chocolate, 
Purple and white make French white, 
Light green and black make dark green, 
White and green make pea green, 
White and emerald green make brilliant 

green, 
Red and yellow make orange. 
White, lake and vermillion make flesh color, 
Umber, white and Venetian make drab, 
White, yellow and Venetian red make cream, 
Blue, black and red make olive, 
Yellow, white and a little Venetian red make 

buff, 
White and green make bright green. 
White, blue and grey make pearl grey. 



ACID COPPER PLATING SOLUTION. 

Standard Formula: 

Crystallized copper sulphate. 32 Ounces. 

Water 1 Gal. (U.S.) 

Copper Determination: 

Put 5 c.c. of the solution using a pipette, in- 
to a 250 c.c. beaker. Add about 100 c.c. water 
and 25 c.c. cone, sulphuric acid. Cut off a 



60 Electro-Platixg and Analysis of Solutions 

small strip (about l l / 2 inches square) of alumi- 
num foil and place it in beaker. Heat gently 
and the copper will be precipitated out as met- 
allic copper. When solution becomes white, 
the copper can be filtered off using glass wool 
in funnel in place of filter paper. The filtrate 
is tested for copper by passing in H 2 S gas, 
which gives a black precipitate of copper sul- 
phide if it is present, indicating that it was not 
all precipitated by the aluminum foil. Wash 
the copper on the funnel once with hot water, 
then dissolve off the copper from the alum- 
inum foil with warm cone, nitric acid pouring 
into funnel and receiving the dissolved copper 
in an Erlenmeyer flask. When all the copper 
is dissolved, the solution is heated until all ni- 
trous fumes are gone, then add ammonium 
hydrate in slight excess and evaporate until 
most of the free ammonia has disappeared. 
Acetic acid is added in excess and heated. If 
solution is not clear it should not be heated 
too much as some of the copper will be lost by 
volatilization. When all the copper is in solu- 
tion cool and add ten grams potassium iodide, 
making sure that all of it is dissolved before 
beginning titration. The free iodine that is 
liberated in the reaction is titrated with stand- 
ard sodium thiosulphate solution, using starch 
as an indicator. The reaction between the 
copper acetate and potassium iodide is the 
formation of copper iodide and the liberation 
of iodine. 



Electro-Plating and Analysis of Solutions 61 

When the potassium iodide is added a yel- 
low precipitate of cuprous iodide (Cu 2 L) is 
thrown down. The starch is not added until 
towards the end of the titration. It produces 
a lilac color and the potassium thiosulphate 
solution is added slowly until one or two 
drops shows a change to a cream which re- 
mains permanent and is not changed by the 
addition of more sodium thiosulphate solution. 

Calculation : 

Multiply the number of c.c. of sodium thio- 
sulphate used by the copper sulphate (Cu S 
4 5 H20) value for 1 c.c, then divide by 5. 
The result is multiplied by 133.54 which gives 
ounces (av.) of copper sulphate per gallon 
(U. S.) 

The following example will illustrate it : 
Used 61.0 c.c. sodium thiosulphate solution, 
the copper sulphate value for 1 c.c. is .01964. 
This multiplied by 61 will equal 1.19804, then 
divided by 5 will equal .2396 ; multiply this by 
133.54 will equal 32 ounces of copper sulphate 
(Cu S Oj 5 H 2 0) per gallon. 

Standard sodium thiosulphate: 

Dissolve 39.2 grams of C. P. sodium thio- 
sulphate in water and dilute to two liters. 
This solution is quite stable. A slight decom- 
position might occur soon after making the 
solution due to carbon dioxide or oxygen in 
the water. The solution should be kept in a 
brown bottle as actinic light will decompose 



62 Ei fctro- Plating and Analysis of Solutions 

it. To standardize, take one gram of pure 
copper foil and dissolve in about 20 c.c. dilute 
nitric acid. When dissolved, dilute to 250 c.c. 
Then take out 50 c.c. with pipette (this is 
equivalent to .2 grams of copper) into an Er- 
lenmeyer flask. Boil out nitrous fumes; then 
add ammonium hydrate in slight excess and 
evaporate until most of the free ammonia has 
disappeared. Acetic acid is added in excess 
and heated if solution is not clear. When all 
the copper is in solution, cool and add ten 
grams of potassium iodide. Then titrate with 
the sodium thiosulphate solution. The end 
point obtained when standardizing should be 
remembered and be the same when titrating 
samples. 

The number of c.c. of sodium thiosulphate 
used is divided into .2 grams, and the result 
will be the number of grams of copper per ex., 
and this multiplied by 3.9283 will give the cop- 
per sulphate (Cu S 4 5 H 2 0) value of 1 c.c. 
of the solution. 

Starch Solution: 

Mix 0.25 gram of potato starch with 10 c.c. 
cold water; then add to boiling water with 
constant stirring to make about 400 c.c. When 
cold, use about 1 c.c. for titrating. It decom- 
poses very readily and should be prepared 
fresh every day. It produces an intense blue 
with iodine, and if brownish red indicates de- 
composition. The following are the reactions 
that occur : 



Electro-Plating and Analysis of Solutions 63 

Copper acetate reacts with potassium iodide 
liberating free iodine as follows : 

2 Cu (C 2 H, 2 ) + 4K I = Cu 2 L + 4 
(K C 2 H 3 2 )'+ 2 I 

The free iodine colors the solution brown. 
The iodine reacts with the sodium thiosul- 
phate forming sodium iodide and sodium tet- 
rathionate. 

2 Na 2 S 2 3 -f- 2 I = 2 Na I + Na 2 S 4 O e . 
The blue compound that is formed when 
starch is mixed with iodine is of unknown 
composition. It behaves towards sodium thio- 
sulphate exactly as free iodine, and the reac- 
tion occurs as in the above equation. 

Sulphuric Acid determination: 

Measure out 5 c.c. of the solution with pip- 
ette into a 400 c.c. beaker; add 100 c.c. water 
and about 1 drop of a 5% solution of methyl 
orange. The solution will be a bright red. 
Place beaker on a white surface. From a 50 

N 
c.c. burette add — sodium hydrate until solu- 

1 
tion in beaker becomes a golden yellow. This 
indicates the end point. The number of c.c. 

N 
used of the — sodium hydrate is noted and cal- 

1 
culated as follows : 

N 
The number of c.c. — sodium hydrate used 
1 



64 Electro- Plating and Analysis of Solutions 

is multiplied bv the sulphuric acid value of 

N 
1 c.c. (exactly — Na O H will be .04904 

1 
grams) then divided by 5, and the result mul- 
tiplied by 133.54 will give ounces (av.) of sul- 
phuric acid (100% per gallon (U. S.). 
Example : 

'N 
Used 8.0 c.c. — Na O H. The sulphuric 
1 
acid value of 1 c.c. is .04904. Multiply this by 
8 will give .39232 and divided by 5 will equal 
.07846; then multiply by 133.54 will give 10.48 
ounces (av.) of sulphuric acid per gallon 
(U. S.). 

N 
Standard — Sodium Hydrate : 
1 
Dissolve 80 grams C. P. sodium hydrate in 
water and dilute to two liters. Standardize 

N 
with — sulphuric acid, using methyl orange 

1 
as an indicator. 
1 c. c. exactly N Na O H = .0400 grams 

T Na O H 

1 c. c. '" " = .04904 grams 

H 2 S 4 . 
The following reactions occur in titrating: 
H 2 S 4 + 2 Na O H = Na 2 S 4 + 2 H 2 O 
Methyl orange is changed by alkalies to a yel- 



Electro- Plating and Analysis of Solutions 65 

low and by acids to a pink red, therefore in 
titrating acidity it will indicate when suffi- 
cient sodium hydrate has been added, as an 
excess will change color to a yellow. 
Copper Determination: 

Put 10 c.c. of the solution with a pipette 
into a 250 c.c. beaker. Add 15 c.c. cone. H CI, 
Care should be taken not to inhale the gas, 
as it is very poisonous. Boil a few minutes* 
then add 5 c.c. H 2 2 and continue boiling for 
fifteen minutes, adding water occasionally for 
the loss by evaporation. After decomposition 
of the cyanide 100 c.c. water are added and 
solution heated, then H 2 S gas passed in for 
about ten minutes to precipitate the copper 
as Cu S. After precipitation, place beaker on 
water bath until precipitate collects and falls 
to the bottom, then filter it off washing with 
Ho S water three or four times. The filtrate 
is set aside for zinc determination. The filter 
paper containing the copper sulphide is re- 
moved from the funnel and the sulphide 
washed into a 250 c.c. beaker. The small por- 
tions that cannot be removed by washing can 
be dissolved by pouring on cone, nitric acid, 
adding sufficient finally to dissolve all of the 
Cu S. Boil out excess of H N O s and filter off 
any sulphur that has collected in small yellow 
lumps. Filter into an Erlenmeyer flask and 
neutralize with N H 4 O H, adding slight ex- 
cess; then boil until N H 4 OH is faint. Add 
excess of acetic acid and boil for a couple of 



66 Electro- Plating and Analysis of Solutions 

minutes until ail the copper salts are in solu- 
tion. Cool to the ordinary temperature (to 
prevent volatilizing free iodine) and add 10 
grams of K I. The free iodine is titrated with 
standard sodium thiosulphate solution until 
the brown tinge has become faint then add 
sufficient starch solution to produce a decided 
blue color the titration is continued with 
vigorous shaking until a permanent cream 
color is produced. The starch solution should 
be weak as otherwise it tends to occlude 
iodine forming very small lumps that are not 
readily acted on by the thiosulphate solution. 
About .25 gram in 400 c.c. of water is the cor- 
rect strength to use. 



BRASS PLATING SOLUTION. 

Standard formula : 

Dry copper carbonate 12 Ounces. 

Dry zinc carbonate 7 Ounces. 

Potassium cyanide 25 Ounces. 

Water 1 Gallon. 

Calculation : 

Multiply the number of c.c. of sodium thio- 
sulphate used by the copper value for 1 c.c. 
(Cu C Oh Cu (OH) 2 Ha O). The formula dif- 
bonate as figured from its theoretical formula 
multiply by 1.8812. This will give copper car- 
gallon. To convert this to copper carbonate. 
Then divide by 10. The result multiplied by 
133.54 will equal ounces (av.) of copper per 
fers according to the method of manufactur- 



Electro- Plating and Analysis of Solutions 67 

ing the copper carbonate. A true basic copper 
carbonate having the above formula would 
analyze as follows : 

Cupric oxide (Cu O) 66.54 

Carbon dioxide (CO,) 18.40 

Water (H,6) 15.06 

100.00 
Sodium Thiosulphate : 

Use the same solution as is used for acid 
copper. The copper carbonate (Cu C O s Cu 
(OH), H 2 

Value for 1 c.c. is found by multiplying the 
copper value by 1.8812 or to find any other 
value multiply by the following factors : 

Cu X 1.2517 = Cu O 

Cu O X 0.7989 == Cu 

Cu X 1.8812 = Cu C 8 Cu (OH), H 2 

Zinc Determination : 

The filtrate from the Copper Sulphide is 
boiled to expel H 2 S, then neutralized with 
N H 4 O H. Add 10 c.c. cone. H CI and 5 
grams of ammonium chloride and dilute to 
250 c.c. Heat solution nearly to boiling, then 
take out a portion, about 50 c.c. into another 
beaker ; run into the remaining portion with 
vigorous stirring standard potassium ferro- 
cyanide solution until a brown tinge is pro- 
duced, when a few drops is taken out 
on a porcelain plate and mixed with 
a solution of uranium acetate. The portion 
that was taken into the beaker is then added in 



68 Electro- Plating and Analysis of Solutions 

small portions at a time continuing the titra- 
tion after each portion is added. After the 
addition of the last portion the ferrocyanide 
solution is added by drops until the end point 
is obtained as a brown color with the uranium 
acetate. A correction for the reaction with 
the indicator, having the same conditions as, 
above — that is, volume, temperature, ammon- 
ium chloride and free acid, but without the 
zinc — is determined. This correction, which 
will not amount to more than a few tenths of 
a c.c., is always subtracted from the burette 
reading when a titration is made. 

Calculation : 

Multiply the number of c.c. of potassium 
ferrocyanide solution used by the zinc value for 
1 c.c then divide by 10. The result multi- 
plied by 133.54 will equal ounces of zinc per 
gallon. To convert this to zinc carbonate : 
(5 Zn O. 2 C 2 4H 2 0), 
multiply by 1.7315. 

Basic zinc carbonates differ in composition 
like the copper carbonate according to the 
method of manufacture. The true basic zinc 
carbonate has the above formula and would 
test as follows : 

Zinc oxide (ZN O) 71.77% 

Carbon dioxide (C CX) 15.52% 

Water (H 2 ) 12.71% 

100.00% 



Electro- Plating and Analysis of Solutions 69 

Potassium Ferrocyanide : 

48.6675 grams of Merck's pure potassium 
ferrocyanide are dissolved in water and made 
up to 2250 c.c. and kept in a brown bottle. 

Uranium Acetate: 

Dissolve 4.4 grams of Merck's salt in 100 
c.c. of water and 2 c.c. of acetic acid. 

Standardizing the potassium ferrocyanide 
solution : 

0.3 grams of Merck's pure zinc are dissolved 
in 25 c.c. of dilute H CI (1 part H CI, 3 parts 
H 2 0), then add 4 grams of pure N H 4 CI and 
dilute to 250 c.c. with water and heat almost 
to the boiling point. Then run in about 58 c.c. 
of the potassium ferrocyanide solution, stir- 
ring vigorously. Take out two or three drops 
on a plate covered with parafine and mix with 
a drop or two of the uranium acetate solution. 
Continue the titration until the first faint 
tinge of brown red color. Another portion 
of 0.3 grams of zinc is also titrated and should 
agree with the first portion within 0.1 c.c. A 
correction for the reaction, having the same 
volume of H 2 0, H CI, and same number of 
grams of N H 4 CI but without the zinc, is 
determined. This correction is deducted from 
the number of c.c. used in titrating the 0.3 
grams sample. 

To find the value of 1 c.c. of potassium 
ferrocyanide solution in terms of zinc, divide 
0.3 by the corrected c.c. of the ferrocyanide 



70 Electro- Plating and Analysis of Solutions 

used and the result will be the grams of zinc 
in 1 c.c. of the potassium ferrocyanide solu- 
tion. To find the value in terms of zinc ox- 
ide or carbonate, multiply the zinc value by 
the following factors : 

Zn X 1.2448 = ZnO 

Zn O X 0.8034 = Zn 

Zn X 1.7345 = 5 Zn O. 2 C 2 . 4 H 2 

The reactions that occur in titrating be- 
tween zinc chloride and potassium ferrocyan- 
ide vary according to temperature, quantity 
of solution, and amount of acid. 

The probable reactions, using the above 
methods, are as follows: 
4 Zn CI, + 2 K 4 Fe (C N) B = 8 K CI + 2 

Zn 2 Fe C N, 
A secondarv action then takes place : 
6 Zn. Fe (C N) 6 + 2 K 4 Fe (C N) e = 4K, Zn 3 

(Fe (C N) 6 " ) 2 . 



RESULTS OBTAINED BY ANALYSIS 
OF BRASS SOLUTION. 

In making up a brass solution, put in the 
metal at the rate of 5 parts carbonate of cop- 
per, and 3 parts carbonate of zinc. One would 
naturally think when a test was made of this 
solution that the same proportion of copper 
and zinc would be found, but I find that when 
an analysis is made the proportions are quite 
different, as there is always a sediment in the 
bottom of a brass solution, and this sediment 
in my experience is mostly zinc, with a very 
small amount of copper. So do not run away 



Electro-Plating and Analysis of Solutions 71 

with the idea of being able to test your solu- 
tion and get the same amount as you weighed 
and put in, as it seems to be impossible to 
make a brass solution and take up all the 
metal. For instance' try and make up a stand- 
ard brass solution, and that will show you 
that it is next to impossible to take up all the 
metal. I find the best way is to take a small 
amount of solution from the top of one of the 
tanks which is clear, and then standardize it 
by analysis, which will prove to you the true 
amount of metal in the solution. 

For example, make up a solution of 
12 Ounces copper carbonate, 
6 Ounces zinc carbonate, 
and then you say to yourself, I have a solution 
with the above named amounts in it, you are 
wrong as a good part of the. compound is ly- 
ing on the bottom of the tank, and is not 
in solution. 

CYANIDE COPPER PLATING 
SOLUTION. 

Copper Determination: 

Take 10 c.c. of the solution with a pipette 
into a 250 c.c. beaker. Add 15 c.c. cone. H CI. 
Care should be taken not to inhale the gas, 
as it is very poisonous. Boil a few minutes, 
then add 5 c.c. H 2 2 and continue boiling for 
fifteen minutes, adding water occasionally for 
the loss by evaporation. After decomposition 
of the cyanide 100 c.c. of water is added 
and solution heated, then H 2 S gas passed in 



72 Electro- Plating axd Analysis of Solutions 

for about ten minutes to precipitate the copper 
as Cu S. After precipitation place beaker on 
water bath until precipitate collects and falls 
to the bottom, then filter it off washing with 
H 2 S water three or four times. The filter 
paper containing the copper sulphide is re- 
moved from the funnel and the sulphide wash- 
ed into a 250 c.c. beaker. The small portions 
that cannot be removed by washing can be 
dissolved by pouring cone, nitric acid' adding 
sufficient finally to dissolve all of the Cu S. 
Boil out excess of H N 3 and filter off any 
sulphur that has collected in small yellow 
lumps. Filter into an Erlenmeyer flask and 
neutralize with N H 4 O H, adding slight ex- 
cess; then boil until N H 4 O H is faint. Add 
excess of acetic acid and boil for a couple of 
minutes until all the copper salts are in sol- 
ution. Cool to the ordinary temperature 
(to prevent volatilizing free iodine) and add 
10 grams of K I. The free iodine is titrated 
with standard sodium thiosulphate solution 
until the brown tinge has become faint, then 
add sufficient starch solution to produce a 
decided blue color. The titration is continued 
with vigorous shaking until a permanent 
cream color is produced. The starch solution 
should be weak, as otherwise it tends to 
occlude, iodine, forming very small lumps that 
are not readily acted on by the thiosulphate 
solution. About .25 gram in 400 c.c. of water 
is the correct strength to use. 



Electro- Plating and Analysis of Solutions 73 

Calculation : 

Multiply the number of c.c. of sodium thio- 
sulphate used by the copper value for 1 c.c. 
Then divide by 10. The result multiplied by 
133.54 will equal ounces (av.) of copper per 
gallon. To convert this to copper carbonate' 
multiply by 1.8812. This will give copper car- 
bonate as figured from its theoretical formula 
(Cu C 3 Cu (OH) 2 H 2 0). The formula dif- 
fers according to the method of manufacturing 
the copper carbonate. A true basic copper 
carbonate having the above formula would 
analyze as follows : 

Cupric oxide (Cu O) 66.54 

Carbon dioxide (C 2 ) 18.40 

Water (H 2 0) 15.06 

100.00 

Standard Solutions: 
Sodium Thiosulphate : 

Use the same solution as is used for acid 
copper. The copper carbonate (Cu C 3 Cu 
(O H) 2 H.O 

Value for 1 c.c. is found by multiplying the 
copper value by 1.8812, or to find any other 
value multiply by the following factors : 

Cu X 1-2517 = CuO 

Cu O X 0.7989 == Cu 

Cu X 1.8812 = Cu C O, Cu (OH), H 



74 Electro-Platixg axd Analysis of Solutions 

ASSAY TEST OF GOLD IN GOLD 
PLATING SOLUTIONS. 

Apparatus Necessary: 
Evaporating Dish, 
Crucible, 
Gas furnace. 
Cupel mould. 
Balance, 
100 c. c. Graduated flask. 

Chemicals : 

Sodium bicarbonate, 
Lead oxide, 
Argol, 
Bone ash. 
75 c.c of the solution is taken and evapor- 
ated to dryness in an evaporating dish. The 
residue is scraped off and put in a crucible 
(any good sand or clay crucible about 4^ 
inches in height will do) with the following 
charge : 

20 grams Na H C O s (Sodium bicarbonate) 
70 " Pb O (Lead oxide) 

3 " Argol (Cream of tartar) 
The whole is now thoroughly mixed in the 
crucible. It is now ready for the furnace. 
The heat is applied slowly at first, gradually 
increasing till the flux melts. The flux has 
action and appears to boil mildly. The cruci- 
ble is left in the furnace about 25 minutes, 
being occasionally swirled and should not be 
removed until all action in the crucible has 
ceased. 



Electro-Plating and Analysis of Solutions 75 

It is now taken out, swirled and allowed to 
cool. When cool the crucible is broken open 
and a lead button is found in the bottom. This 
button contains the gold and should be freed 
from any particles clinging to it by hammer- 
ing. 

A bone ash cupel is now moulded and baked. 
Cupels are made of bone ash slightly moist- 
ened with water so that the powder will cling 
together. The mixture should be well kneaded 
before being put in the cupel mould. On com- 
ing out of the mould it is slowly baked in the 
furnace and if possible the cupel should be air 
dried for a week or so although this is not es- 
sential. 

The lead button is now put in the cupel and 
is ready for the furnace. A high heat is main- 
tained for a few minutes in order that the lead 
may melt quickly and oxidation commence as 
soon as possible. After the fumes of lead oxide 
are observed to rise from the surface of the 
cupel, the heat is moderated and as free a flow 
of air as possible is given. The lead is lost in 
the air as lead oxide, and a great deal is ab- 
sorbed by the cupel. When all the lead is gone 
the lead loses all lustre. The change of color 
is readily noticed and the cupel is withdrawn 
from the furnace with its small bead of gold. 

The gold is weighed and the pennyweights 
per gallon may be calculated as follows : 

Weight gold X 50.33=number grams per 
gallon. 



76 Electro- Plating and Analysis of Solutions 

Grams per gallon of solution. 
Grams per gallon -r- 1.55=penriyweight per 
gallon. 

NICKEL PLATING SOLUTION. 

Standard Formula: 

Nickel ammonium sulphate (Dou- 
ble nickel salts) 12 ounces. 

Water 1 Gallon. 

Nickel Determination: 

Measure out 25 c.c. of the solution with 
pipette into a 250 c.c. beaker. Add about 2 
c.c. Cone, sulphuric acid and heat almost to 
the boiling point. Pass in hydrogen sulphide 
gas to precipitate any metals such as copper, 
antimony, tin. If present, the precipitate is 
filtered off, washing with H 2 S water, and after 
washing thoroughly the filtrate is boiled to 
expel H 2 S. When entirely free from H 2 S the 
iron is oxidized with 5 c.c. of hydrogen per- 
oxide and boiled until the hydrogen peroxide 
is decomposed (takes about 15 to 20 minutes). 

The iron found in nickel salts is an impurity 
and should be present only as a trace. After 
boiling about twenty minutes the iron is pre- 
cipitated with ammonium hydrate filtered and 
washed once or twice with hot water. The 
precipitate is dissolved in dilute sulphuric acid 
(1 part sulphuric acid and three parts water) ; 
it is then reprecipitated with ammonium hy- 
drate; the second filtrate is then added to the 
first. This second precipitation is necessary 



Electro- Plating and Analysis of Solutions 77 

with large amounts of iron, as the iron oc- 
cludes some of the nickel when it is precipita- 
ted. 

The filtrate is transferred to a 500 c.c. 
beaker, boiled to expel free ammonia and neu- 
tralized with sulphuric acid, using litmus 
paper as an indicator. When solution is neu- 
tral add 2 c.c. Cone, ammonium hydrate and 
dilute solution to 250 c.c. with water; then 
cool to 68° F. It is now ready to be titrated 
with standard potassium cyanide solution as 
follows : Run into the solution from a 50 c.c. 
burette 5 c.c. of standard silver nitrate solu- 
tion (prepared according to directions under 
standard solutions). Add 0.5 c.c. of a 2% 
solution of potassium iodide which throws 
down a precipitate of silver iodide. This pre- 
cipitate is used as an indicator to show when 
all of the nickel has combined with the potas- 
sium cyanide solution as an excess of potas- 
sium cyanide will dissolve it. The beaker con- 
taining the solution is placed on a black sur- 
face and standard potassium cyanide solution 
is run in slowly from a 50 c.c. burette until 
the disappearance of the precipitate of silver 
iodide. This indicates the end point, but 
usually an excess of potassium cyanide is used 
to dissolve the silver iodide, then this excess 
can be found by running in the silver nitrate 
until the first appearance of a precipitate; then 
one or two drops of the potassium cyanide 
solution should give a very clear solution. 



78 Electro- Plating and Analysis of Solutions 

The number of c.c. of silver nitrate and potas- 
sium cyanide used is read of! and amount of 
nickel ammonium sulphate calculated as fol- 
lows : 

The c.c. of silver nitrate used is converted 
into equivalent c.c. of potassium cyanide by a 
factor found under silver nitrate solution. 
After multiplying by this factor the c.c. ob- 
tained are subtracted from c.c. of potassium 
cyanide used, and the result will be the cor- 
rect number of c.c. of potassium cyanide used 
for titrating sample. The nickel ammonium 
sulphate value on 1 c.c. of the potassium 
cyanide solution (See potassium cyanide solu- 
tion for this value) is multiplied by the c.c. 
of potassium cyanide used,- and divided by 25 
c.c, then the result multiplied by 133.54 will 
give the ounces (av.) of nickel ammonium sul- 
phate. 

(Ni S 4 (N H 4 )o S 4 +6H 2 0) per gallon 
(U. S.) 

The following example will illustrate it: 

The factor to convert c.c. of silver nitrate 
to equivalent c.c. of potassium cyanide was 
found to be 0.2. Used 30.4 c.c. of silver ni- 
trate, and multiplying by 0.2 will equal 6.08 
c.c. potassium cyanide. Ran into the solution 
74.88 c.c. of potassium cyanide, then substract- 
ing 6.08 will leave 68.8 c.c. of potassium 
cyanide actually used. 

The value of 1 c.c. of potassium cyanide 
solution in grams of nickel-ammonium sul- 



Electro- Plating and Analysis of Solutions 79 

phate was found to be .03265, which multi- 
plied by 68.8 c.c. will give 2.24632, and divided 
by 25 c.c. will equal .0898, then multiplied by 
133.54 will give 12 ounces of nickel-am- 
monium sulphate per gallon. 

Standard Silver Nitrate Solution: 

Dissolve 11.6 grams of C. P. silver nitrate in 
water and dilute to two liters. This solution 
is to be kept in a brown bottle, as the light 
will decompose it. To find the factor to give 
equivalent c.c. of potassium cyanide solution, 
take 15 c.c. of the silver nitrate, add 2 c.c. 
Cone, ammonia and dilute with water to 250 
c.c. Add 0.5 c.c. of potassium iodide and run 
in potassium cyanide solution slowly until dis- 
appearance of precipitate. The number of 
c.c. used is divided by 15 c.c, and the result 
will be the factor to convert c.c. of silver ni- 
trate to c.c. of potassium cyanide. 

Standard Potassium Cyanide Solution: 

Dissolve 44.5 grams of C. P. potassium 
cyanide (Merck's Reagent) in water and dilute 
to two liters. Solution should be kept in a 
brown bottle and will have to be standardized 
every few days as it does not remain stable. 

Standardize as follows : Weigh 1 gram C. 
P. nickel (Electrolytic) and dissolve in 5 c.c. 
of dilute nitric acid and 10 c.c. of dilute sul- 
phuric acid and a little water. When dis- 
solved, transfer to a 250 c.c. graduated flask; 



Electro- Plating axd Analysis of Solu 



itioxs 



cool, and dilute to 250 c.c. with water. Take 
out 50 c.c. with pipette which is equivalent to 
.2 grams of nickel. (50 c.c. is 1 of 250 c.c. and 

5 
1 of 1 gram is .2 gram). Neutralize with am- 
5~ 

monia; then add 2 c.c. in excess, and titrate 
with the silver nitrate and potassium cyanide, 
as in the directions already given. The c.c. 
of potassium cyanide used is divided into .2 
grams, and the result multiplied by 6.7314 will 
be the nickel-ammonium sulphate (Ni S 4 
(N H 4 ) 2 S O i 6H 2 O) value for 1 c.c. of the 
potassium cyanide solution. 

The following are the reactions that occur : 

Silver nitrate reacts with potassium iodide 
as follows : 

Ag N 3 +K I=Ag I+K N 3 

The reaction of nickel sulphate with potas- 
sium cvanide is as follows : 

Ni S 4 +4K C N=(K C N) 2 Ni (C N) 2 ) + 
K 2 S 4 . 

The silver iodide is dissolved by the potas- 
sium cyanide during titration forming the 
double salt potassium silver cyanide as in the 
following equation : 

Ag I+2K C N= KCN Ag C N + K I. 

If cobalt is present it will be estimated with 
the nickel. Its presence is shown by the solu- 
tion darkening. 



Electro-Plating and Analysis of Solutions 81 

SILVER PLATING SOLUTION. 

Standard Formula: 

Silver Chloride 4 Ounces (av.) 

Potassium Cyanide ... 12 ( a v.) 

Water 1 Gallon (U.S.) 

Silver determination : 
Measure out 25 c.c. of the solution with a 
25 c.c. pipette into a 400 c.c. beaker, using a 
long rubber tube on pipette for aspirating the 
solution so as to prevent it being sucked into 
the mouth. Add 100 c.c. of water to the beaker 
and heat almost to the boiling point, then pre- 
cipitate the silver as silver sulphide (Ag 2 S) 
with hydrogen sulphide gas (H 2 S). AVhen 
complete precipitation has taken place, filter 
off the silver sulphide on an E. and A. filter 
paper 13 cm., washing the precipitate with 
hydrogen sulphide water several times. The 
paper and precipitate is removed from the 
funnel, and the silver sulphide washed from 
the paper into a 250 c.c. beaker with water. 
(The adhering pieces on the paper can be re- 
moved with Cone, nitric acid). The silver sul- 
phide is dissolved in a small quantity of Cone, 
nitric acid, then the solution is boiled to expel 
the nitrous fumes, as their presence will inter- 
fere with the titration. After boiling off the 
nitrous fumes the solution is cooled and 
diluted to about 150 c.c. with water and 
titrated as follows : 

Add 5 c.c. of a cold saturated solution of 
iron alum (ferric ammonium sulphate). If 



82 Electro-Platixg axd Axalysis of Solutions 

the solution becomes turbid, nitric acid is 
added drop by drop until clear. Place the 
beaker on a white surface and add the stand- 
ard N potassium sulphocyanate solution from 

10 
a 50 c.c. burette with constant stirring until a 
faint permanent reddish tinge of ferric sul- 
phocyanate — Fe 2 (S C N) 6 — is produced. 
The number of c.c. used is noted and the 
ounces of silver chloride per gallon calculated 
as follows : 

Multiply the c.c. of N potassium sulpho- 
10 
cyanate used by the silver chloride value for 1 
c.c. (for exactly N it is .01133 grams), then di- 

10 
vide by 25 (number of c.c. taken for analysis). 
This will give the grams of silver chloride in 
lc.c. of the plating solution. To convert this 
to ounces (av.) per gallon (U. S.), multiply 
by 133.54. 

The following example will illustrate it: 
Used 52.3 c.c. N potassium sulphocyanate; 

lb 

multiply by .01133 will equal .74916, and 
divide by 25 will equal .02997 grams silver 
chloride in 1 c.c. of plating solution, then mul- 
tiply by 133.51, and the result will be 4 ounces 
of silver chloride per gallon (U. S.) 



Electro- Plating and Analysis of Solutions S3 

Standard N Potassium Sulphocyanate : 

10 

Dissolve 20 grams of potassium sulphocyan- 
ate in water and dilute to two liters. Stand- 
ardize it by taking 0.4 grams granulated silver 
(999 fine) in a 250 c.c. dilute nitric acid (equal 
parts of cone, nitric acid and water). After 
the silver is dissolved, the solution is boiled to 
expel nitrous fumes. When entirely free from 
nitrous fumes (this is shown by no more yel- 
low fumes coming off) the solution is cooled 
and diluted to 150 c.c. with water; then add 
5 c.c. of indicator (iron alum) and titrate with 
the potassium sulphocyanate solution until 
the first permanent pink is produced. The 
number of c.c. used divided into 0.4 gram, 
will give the grams of silver in 1 c.c. of the 
solution, and this multiplied by 1.3287 will give 
the grams of silver chloride in 1 c.c. of the 
potassium sulphocyanate solution. 

The following are the reactions that take 
place in titrating: 

Ag N Os+K S C N=Ag S C N +K N 3 
An excess of potassium sulphocyanate then 
reacts with iron alum as follows : 

2 Fe N H 4 (S 4 ) +6 K S C N=Fe 2 (S C 
N) e N H 4 ) 2 S 4 +3 K 2 S 4 . 

This method is accurate in the presence of 
copper (not exceeding 70% arsenic, antimony, 
cadmium, lead, bismuth, tin, zinc, iron and 



84 Electro-Plating and Analysis of Solutions 

manganese. Mercury if present will interfere, 
and therefore should be removed before 
titrating. 

Uncombined Cyanide determination: 

Take 10 c.c. of the plating solution into a 
400 c.c. beaker; add about 100 c.c. water and 
2 c.c. of Cone, ammonium hydrate and about 
1 c.c. of 2% potassium iodide solution; then 
run in from a 50 c.c. burette N silver nitrate 

To" 

until a permanent white precipitate of silver 
iodide is formed. This indicates the end point. 
The number of c.c. of silver nitrate used is 
noted and calculated as follows : 

1 c.c. N^ Ag N O 3 =.005202 gms. C. N. The 

To 

number of c.c. Ag N O used times .005202= 
"x" grams C N in 10 c.c. of the plating solu- 
tion. Then "x" grams C N divided by 10 will 
give the grams of C N in 1 c.c. of plating solu- 
tion, which multiplied by 133.54 will be the 
ounces (av.) of C N per gallon (U. S.). 

This determination is figured as C N, not as 
K C N, as the majority of the potassium cya- 
nides on the market contain large quantities 
of Na C N which would be included when 
figuring the uncombined cyanide as K C N. 

The uncombined cyanide is the K C N or 
Na C N that has not combined with the Ag 
CI to form the double salt Ag C N K C N as 
in the equation : 



Electro- Plating and Analysis of Solutions 85 

Ag C1+2K C N=Ag CMC N+K CI. 

In titrating the free K C N or Na C N with 
Ag N Os'the double salt (Ag C N K C N) is 
not titrated by the Ag N 3 , only the free K 
C N or Na C N as in the following equations : 

Ag N 3 +2 K C N=Ag CNKC N+K N 

a ■ 

Then an excess of Ag N O s reacts with the 
Kl as follows : 

Ag N 3 +K I=Ag I + K N 3 

Standard N Silver Nitrate Solution: 

10 

Dissolve 33.978 grams of pure silver nitrate 
in water and dilute to two liters. To stand- 
ardize take 0.25 grams C. P. sodium chloride 
(Merck's Reagent) in a 400 ex. beaker; add 
100 c.c. water, and when all of the salt has 
been dissolved add 1 c.c. of a 2% solution of 
neutral potassium chromate as an indicator. 

Place beaker on a white surface and titrate 
with the silver solution from a burette until 
a faint red tinge is obtained. The end point 
is somewhat difficult to distinguish. The faint 
red tinge can be more distinctly seen if an- 
other beaker containing 150 c.c. water and 1 
c.c. of the chromate solution is compared with 
it. The sodium chloride solution should be 
number of c.c. of silver nitrate solution used 
neutral or faintly alkaline and cold. The 
(exactly N would take 42.76 c.c.) divided into 

10 



86 Electro- Plating axd Analysis of Solutions 

0.25 grams sodium chloride will give the num- 
ber of grams of sodium chloride in 1 c.c. of the 
silver nitrate solution. The other values can 
be found by multiplying the sodium chloride 
value by the following factors : 
Na'ci X 0.8898 = CN 
" 2.2275 = KCN 
" 1.6767 = NaCN 
1 c.c. Exactly N_AgNO s = .005202 gms. CN 

' 10 
1 c.c. " NAgN0 3 = .01302 " KCN 
10 

1 c.c. " JN[AgN0 3 = .009802 "NaCN 
10 

1 c.c. " N_AgNO a = .005846 " NaCl 
10 



CYANIDE DETERMINATION IN 
POTASSIUM CYANIDE. 

Weigh off about 15 grams of the potassium 
cyanide in a tared weighing bottle, dissolve in 
water without heat and dilute to 500 c.c. 

Take out 10 c.c. with pipette into a beaker, 
add 2 c.c. of Cone. N H 4 O H and 1 c.c. K I 
solution (2%) and about 100 c.c. water, then 
run in N Ag N O s from a burette until a per- 

10 
manent white precipitate of silver iodide is 
formed. The number of c.c. of Ag N O s used 



Electro- Plating and Analysis of Solutions 87 

multiplied by .005202 and divided by the 
weight taken, then multiplied by 100 = % CN 
in sample. 

Example : 

15.281 grams of potassium cyanide were dis- 
solved and diluted to 500 c.c., then 10 c.c. 
(.3051 grams) required 23.45 c.c. N^ Ag N 3 

10 

23.45 X .005202=.121988-r-.3051=.3999X100 

=39.99% C N. 

Factors : 

CN X 1-8843 = NaCN 
CN X 2.5033 = KCN 
NaCN X 0.53071 = CN 
KCN X 0.39947 = CN 
Ag X 1-3287 = AgCl 
Ag X 0.4822 = CN 
AgCl X 0.36291 = CN 
Ag X 0.90847 = KCN 
Ag X 0.68382 = NaCN 



Electro- Plating and Analysis of Solutions 




Electro- Plating and Analysis of Solutions 89 

TOTAL POTASSIUM AND SODIUM 

CYANIDE DETERMINATION 

IN SILVER SOLUTION. 

In an apparatus as shown below distill 10 
c.c. of silver solution to be tested for cyanide, 
potassium cyanide, or sodium cyanide, as fol- 
lows : 

Take 10 c.c. of silver solution, add 10 c.c. of 
water (H 2 0), and place in Jena Kjeldahl Flask 
(C) connected with stop cock funnel (D) and 
connect with glass tube into Liebig Condenser 
(F). On receiving end of condenser have bot- 
tles (K & M) connected to collect steam. 
Place in funnel (D) 25 c.c. sulphuric acid 
(H 2 S 4 ) and 25 c.c. water (H 2 O) and then 
place in bottle (K) at receiving end of con- 
denser 50 c.c. water (H 2 O) and 1 gram of 
sodium hydrate (Na OH). Add the sulphuric 
acid and water that is in funnel (D) to the sil- 
ver solution in Kjeldahl Flask (C) drop by 
drop while over flame (B). A slow stream of 
water must be kept running through the con- 
denser (F) by connecting the lower rubber 
'tube (J) with a water cock (O). When the 
solution is boiled in the Kjeldahl Flask (C) by 
means of a Bunsen burner flame (B) placed 
under flask, the steam passes into the inner 



90 Electro- Plating and Analysis of Solutions 

tube of the condenser (F). As this is sur- 
rounded by cold water the steam condenses 
and the distilled cyanide solution collects in 
the receiver (K) at the other end of con- 
denser. When all the cyanide has come over, 
you will notice acid fumes in the flask. Then 
titrate the cyanide solution which has been 
collected in the receiver with N silver nitrate 

10 
solution (Ag N 3 ). 

Before titrating-, take cyanide solution col- 
lected from condenser, and add 1 c.c. potas- 
sium iodide solution (K I) 2% solution, and 
about 100 c.c. water, then run in from a bur- 
ette N silver nitrate until a permanent white 

10 
precipitate of silver iodide is formed. This in- 
dicates the end point. The number of c.c. of 
silver nitrate used is noted and calculated as 
follows : 

1 c.c. N_ Ag N O 3 =.005202 gms. C N. The 
10 
number of c.c. Ag N 3 used times .005202= 
"x" grams C N in 10 c.c. of the plating solu- 
tion. Then "x" grams C N divided by 10 will 
give the grams of C N in 1 c.c. of plating solu- 



Electro- Plating and Analysis of Solutions 91 

tion, which multiplied by 3785 will be the 
grams cyanide per gallon. As there are 30 
grams in one ounce, divide by 30 which will 
be ounces per gallon. As there is only about 
39 to 40% cyanide in potassium cyanide, you 
multiply the amount of cyanide by 2.5, which 
will give you the amount of potassium cyanide 
per gallon in silver solution, minus 20% which 
is lost. 

The 20% loss in the above method is due 
to the cyanide decomposing, etc., and about 
7% of it turns into carbonate of potassium. 



POTASSIUM CARBONATE IN SILVER 
SOLUTION. 

In an apparatus as shown in cut distill 5 c.c. 
of silver solution to be tested for potassium 
carbonate as follows : 

Take 5 c.c. of silver solution, add 5 c.c. wa- 
ter, and place in Jena Kjeldahl flask connected 
with stop cock funnel, and connect with glass 
tube into Liebig Condenser. On receiving 
end of condenser have bottle connected to col- 
lect steam. Place in funnel 25 c.c. sulphuric 
acid (H 2 S 4 ) and 25 c.c. water (H 2 O) and 
then place in bottle at receiving end of con- 
denser 50 c.c. saturated solution of barium 
hydroxide and water. This is water that has 
taken into solution all the barium hydroxide 
that it will hold. 



92 Electro- Plating and Analysis of Solutions 

Add the sulphuric acid and water that is in 
funnel to silver solution drop by drop while 
over flame. A slow stream of water must be 
kept running through the condenser by con- 
necting the lower rubber tube with a water 
cock. When the solution is boiled in the 
Kjeldahl flask by means of a bunsen burner 
flame placed under flask, the steam passes 
into the inner tube of the condenser. As 
this is surrounded by cold water the steam 
condenses and the potassium carbonate in the 
solution is broken up and carbon dioxide 
(C 2 ) is distilled over the carbon dioxide 
combines with the barium hydroxide to form 
barium carbonate and water after the follow- 
ing equation : 

C 2 +Ba (O H) 2 = Ba C 3 +H 2 O. 

The barium carbonate is a white precipitate. 

When all is distilled over acid fumes will be 
seen in the flask, and the flame is taken away. 

The barium carbonate is filtered off and 
heated in a weighed crucible. 

When heated the barium carbonate is 
changed to barium oxide and is then weighed 
as such. 

Ba C 3 =Ba O + C 2 . 

The barium oxide is figured to potassium 
carbonate in oz. per gal. as follows : 

Wt. Ba O multiplied by .9=Wt; K 2 C O s . 

Wt. K 2 C 3 -f-No. of c.c. taken. Then mul- 
tiplied by 133.54=no. ozs. of K 2 C 3 in 1 gal- 
lon of silver solution. 



Electro-Plating and Analysis of Solutions 93 



APPARATUS AND CHEMICALS NECES- 
SARY FOR THE METHODS OF 
ANALYSIS OF THE SOLUTIONS. 

Yz pound ...Potassium Iodide, C.P. cryst. U. 

S.P. 
3^2 pound ...Potassium Sulphocyanate, C.P. 

1 ounce . . . Phenolphtaleine, Pure, 
Y^ pound ...Acid Carbolic, C.P. 

2 ounces ..Silver Nitrate, C.P. 

1 pound . . . Sodium Hydroxide Electrolytic 

sticks. 
1 ounce . . . Nickel Metal Co. free Gran. C.P. 
25 grams . . . Copper Electrolytic Foil Kb. 
Reag. 
y 2 pound ...Aluminum Metal Foil 5/1000 in., 
pure. 
1 pound . . . Hydrogen Peroxide Marchand, 
Yz pound ...Ammonium Molybdate C.P. 

5 pounds . .Iron Sulphide Broken Plates 
1 book ....100 Strips each Litmus Blue 
1 book ....100 Strips each Litmus Red 

4 pounds . .Ammonium Hydrate 26 deg. 

Baker's anal. chem. 
9 pounds . .Acid Sulphuric, 1 

6 pounds . .Acid Hydrochloric 

7 pounds ..Acid Nitric 

1 Bunsen Burner, 

4 feet Rubber Tubing, Black, % 6 inch 

diam., (4 ozs.) 

3 feet Rubber Tubing, % inch diam., (6 

ozs.) 



94 Electro- Plating and Analysis of Solutions 

1 . . . . , Tripod, Iron, 

3 Beakers, Jena, Griffin's, 250 c.c, 

2 ditto 400 c.c, 

2 . ditto 600 c.c. 

2 Flasks, Jena Erlenmeyer 500 c.c. 

1 Cylinder, Lipped, Graduated 100 

c.c. 

2 Burettes, Mohr's, 50 c.c. 1 / 10 c.c. 

subdivisions, 

1 ditto 100 c.c. y 10 c.c. 

subdivisions, 

1 Support for Burettes, 

1 Flask, 250 c.c. 

1 " 1000 c.c. 

Reagent Bottles White Labels 
and Black Letters : — 

1 Reagent Bottle 12 oz. "Acid Sul- 
phuric Cone." 

1 Reagent Bottle 12 oz. "Acid Sul- 
phuric Dil." 

1 Reagent Bottle 12 oz. "Acid Hy- 
drochloric." 

1 Reagent Bottle 12 oz. "Acid Ni- 
tric." 

1 Reagent Bottle 12 oz. "Ammoni- 

um Hydrate." 

2 Funnels, Glass, 3 inch diameter, 

1 Nest of three Funnels, Glass 

6 Funnels Cylindrical, 2 ozs., 

1 Pipette 5 c.c. 

1 " 10 c.c. 

1 " 25 c.c. 



Electro- Plating and Analysis of Solutions 95 

1 Pipette 50 c.c.' 

1 " 100 c.c. 

1 Thermometer 400 deg. F., 

1 box Labels, #201, 

1 box " 223, 

1 Spatula, Blade 3 inches, 

1 Gas Generator, Dudley's for H2S 

1 pound . . . Glass Tubing, % inch external di- 
ameter, 

1 pound . . . Glass stirring rods, assorted sizes, 

1 File, Triangular, 4 inch, 

1 Wash Bottle, 1 Pint, 

1 Wash Bottle, 1 Quart, 

1 Support for Funnels, 

2 pkgs. . . . Filter Papers, E. & A. diameter 13 

cm., 

3 Watch Glasses 3% inch diameter, 

3 " " 4 inch diameter, 

y 2 dozen ,. . .Test Tubes 6x^ inch., 

1 Support for 13 Test Tubes, 

1 Kjeldahl Connecting Bulbs Tube, 

small, 

1 Condenser, Liebig end drawn out 

15 inches, 

2 Drying Tubes (Peligot Tubes) 6 

inch., 

3 Rubber Stoppers, solid, 

No. 1, 6 ozs. 

3 Rubber Stoppers, solid, 

No. 5, 6 ozs. 

3 Rubber Stoppers, solid, 

No. 6, 6 ozs. 



96 Electro- Plating and Analysis of Solutions 

ANTIDOTES FOR POISONS USED IN 
PLATING ROOM. 

Nitric, hydrochloric or sulphuric acids : Ad- 
minister abundance of tepid water to act as 
an emetic, or swallow milk, the white of eggs, 
some lime, or a mixture of chalk and water. 

If those acids in a concentrated state have 
been spilled on the hands or any part of the 
skin, apply a mixture of whiting and olive oil. 
If the quantity is very small, simple swilling 
with plenty of cold water will suffice. 

Useful Mixture : 

Mixture, is in cases of burning with strong 
sulphuric acid, is formed with 1 ounce of quick 
lime slacked with % of an ounce of water, then 
adding to a quart of water. After standing 2 
hours, pour off the clear liquid and mix it with 
olive oil to form thin paste. 

Potassium Cyanide, Hydrocyanide Acid, etc. 

If cyanides, such as a drop of an ordinary 
plating solution, has been accidentally swal- 
lowed, water as cold as possible should be run 
on the head and spine of the sufferer, and a 
dilute solution of iron acetate, citrate, or tar- 
trate administered. 

If hydrocyanic acid vapors have been in- 
haled, cold water should be applied as above, 
and the patient be caused to inhale atmos- 
pheric air containing a little of chlorine gas. 



Electro- Plating and Analysis of Solutions 97 

It is a dangerous practice to dip the arms 
into a plating solution to recover any work 
that has fallen off the wires, because the skin 
often absorbs cyanide liquids, causing painful 
sores, in such a case, wash well with water 
and apply with olive oil and lime water. 

Mixture, Alkalies: 

These bodies are the opposite to acids in 
character, so that acids may be used as anti- 
dotes. It is preferable to employ weak acids, 
such as vinegar or lemonade ; but if these are 
not at hand, then use exceedingly dilute sul- 
phuric or even nitric acid diluted, so that it 
just possesses a decidedly sour taste. After 
about 10 minutes take a few teaspoonsful of 
olive oil. 

Mercury Salts. 

The white of an egg is the best antidote 
in this case. 

Sulphur or sulphureted hydrogen are also 
serviceable for the purpose. 

Copper Salts. 

The stomach should be quickly emptied by 
means of emetic, or in want of this, the patient 
should thrust his finger to the back of his 
throat so as to tickle the uvala, and thus in- 
duce vomiting. After vomiting, drink milk, 
white of an egg, or gum water. 



98 Electro- Plating axd Analysis of Solutions 

Lead Salts: 

Proceed as in case of copper salts. Lemon- 
ade, soda water and sodium carbonate are 
also serviceable. 

Acid Vapors: 

Admit immediately an abundance of fresh 
air, and inhale the vapors of ammonia, or a 
few drops of ammonia may be put into a 
glass of water and the solution drank. Take 
plenty of hot drinks, and excite warmth by 
friction. Employ hot foot-baths to remove 
the flood from the lungs. Keep the throat 
moist by sipping milk. 

Removal of Stains, etc. 

To remove stains of copper sulphate, or 
salts of mercury, gold, silver, etc., from the 
hands, wash them with a very dilute solution 
of ammonia, and with plenty of water; if the 
stains are old ones, they should be rubbed with 
the strongest acetic acid, and then treated 
as above. 

GREASE, OIL, TAR, ETC., may be re- 
moved from the hands or clothes by rubbing 
with a rag saturated with benzine, turpentine,, 
or carbon bisulphide. 



Electro- Plating and Analysis' of Solutions 99 



CONTENTS. 



ILLUSTRATIONS. 

Page 

Apparatus for Salt Water Gold Plating 39 

Apparatus Necessary for Determination of Cyanides. .. .88 

Conductors 2 

Motor Generator "Excel- All" 20 

"None-Such" Carboy Rocker 26 and 36 

"None-Such" Plating Barrel 25 

"None-Such" Plating Barrel, Table Type 29 

Plan of Plating Room 16 

Plating Dyanamo, "Excel-All", 17 

Plating Rheostat 24 

Rheostat and Wattmeter 41 

Sprayers for Lacquering 46 

Standard Ammeter 18 

Standard Voltmeter 21 

Steel Ball Burnishing Barrel, Double 44 

Steel Ball Burnishing Barrel, Single .43 

ARTICLES. 

Acid Copper Plating Solution 47-59 

Acid Dip for Matt Finish on Brass 52 

Acid, Soldering 51 

Air Brushes, Uses of 46 

Apparatus and Chemicals Necessary for Analyzing, 

List of 93 

Arsenic, to Dissolve 49 

Barbadienne Bronze, Formula for 53 

Barrel Plating 25 

Blue Oxidize on Any Metal 51 

Brass, Black Dip on 57 

Brass Plating Solution, Chemical Determinations in ....66 

Brass Plating, Solution for 22-66 

Brass Solution 48 

Brass, Steel Color on 47 

Bronze Solution 56 

Bronze Terra Cotta 55 

Burnishing with Steel Balls 42 

Calculations for Chemical Analysis of Solutions 

61, 63, 65, 66, 67 and 73 



100 Electro- Plating and Analysis of Solutions 



Page 

Casket Hardware, to Silver Plate 27 

Cast Iron, to Clean and Cleaning Solution for 3 

Chemicals Used in Plating Room, List of . . .45 

Chloride of Silver, Flux for Clearing 53 

Conductors, Various Kinds 2 

Copper or Brass, to Color Dark Brown 36 

Copper, Dark Brown, Drab 48 

Copper, Cyanide, Solution 48 

Copper, Fine Brown Bronze on 53 

Copper, Jet Black on .55 

Copper Plating, Solution for 21 

Copper, Red, Solution 48 

Copper, Royal Formula for 48 and 56 

Copper, to Determine in Acid Copper Solution 59 

Crystallized Tin Finish 54 

Cyanide Copper Plating Solution, Analysis of 71 

Equations, Some Simple Plating 8 

Etching Paint for a Stop Off 58 

Electrical Terms, Definitions of 1 

Elements, a List of the 6 

Formula for Color Making Paints and Inks 59 

French Grey, Black Nickel Smut for 57 

Galvanizing Solution 49 

Gilding Solution for Table Ware 34 

Gilders Wax 35 

Gold, Assay Test of Any Gold Solution .74 

Gold Dip Solution 52 

Gold, Green, Solution for 37-51 

Gold Plating, 14 to 18 Karat Color Directions for 35 

Gold, Precipitate of 49 

Gold Strip, Formula for 51 

Gold, to Recover, From an Old Solution 58 

Gun Metal Finish 47 

Holloware, to Silver Plate 31 

Iron, Bright Pickle for 50 

Lacquer, Points on 39 

Lacquer, Water Dip, Use of 41 

Lead and Spelter, to Silver Plate 32 

Metals, to Clean Before Plating 4 

Metric Equivalents, Various 13 

Nickel, Black, Solution 50 and 56 

Nickel Determination 76 

Nickel Plating Solution, Analvsis of 76 



Electro-Plating and Analysis of Solutions 101 

Page 

Nickel Plating, Solution for 19 

Old Ivory Finish 26 

Ormolu Gold Finish on Lead Work 37 

Plating Room, Electrical Requirements Necessary for 

the 15 

Poisons Used in Plating Rooms, Antidotes for 96 

Potassium Cyanide, Standard, Solution 79 

Potassium Cyanide, to Determine Cyanide in 86 

Potassium, Hydro Sulphuret of 50 

Quick Electrotype Formula 50 

Results Obtained by Analysis of Brass Solution 70 

Rose Gold, Directions for Finishing 33 

Salt Water Gold Solution, Outfit for 39 

Sectional Gold, Paint for 55 

Silver Dip Solution 56 

Silver, Flux for Melting 52 

Silver Nitrate, Standard, Solution 79 

Silver Plating Solution, Standard Formula for 81 

Silver Solder 56 

Silver Solution, Brightener for 37 

Silver Solution, Potassium Carbonate in 91 

Silver Solutions, Simple Method for Testing 54 

Silver Solution, Total Potassium and Sodium Cyanide 

in 89 

Silver, to Separate, from Copper 57 

Silver, to Strip, from Steel 58 

Silver White Finish, Solution for 26 

Strip for Brass, Copper or German Silver 49 

Stains, to Remove 98 

Steel, Blue Color on 52 

Steel Knives, to Silver Plate 30 

Sterling Silver, to Remove Fire Stains from -. 58 

Sulphuret of Copper, to Detect Iron in 55 

Sulphuric Acid, Determination in Acid Copper Solution 63 

Tin, to Crystallize 54 

Tin Solution 49 

Verde Antique Paint 57 

Verde Green Solution 52 

Weights and Measures, Tables of Various Kinds of . . 9 
Zinc, Determination in Brass Plating Solution 67 



237 90 











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